The Garden Shed

A Community Newsletter published by the Piedmont Master Gardeners

October 2022-Vol.8, No.10

 

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  Soil Erosion

How to Grow Garlic

The Edible Garden in October

The Ornamental Garden in October

Compact Versions of Commonly Grown Trees and Shrubs

For comments, questions or suggested topics for future Garden Shed articles contact us at: garden-shed@piedmontmastergardeners.org.

If you have specific gardening questions or need help to solve a gardening problem, our Horticultural Help Desk is a free community resource and can be contacted at 434-872-4583 or by email: albemarlevcehelpdesk@gmail.com.

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Table of Contents

In the Edible Garden

How to Grow Garlic

By Cleve Campbell

Garlic is easy to grow and now's the time to plant it!

Tasks and Tips

The Edible Garden in October

By Ralph Morini

As the frost approaches we finalize our planting and harvests and prepare our beds and perennial plants for winter.

Tasks and Tips

The Ornamental Garden in October

By PAT CHADWICK

October is glorious in the ornamental garden, but it is also one of the busiest months for gardeners.

In the Ornamental Garden

Compact Versions of Commonly Grown Trees and Shrubs

By Pat Chadwick

If gardening space is at a premium in smaller landscapes, planting compact or dwarf trees or shrubs may be the perfect solution.

Feature

Soil Erosion

By Linda Blum

We Must Minimize Erosion to Improve Plant Health and Environmental Quality

Upcoming Events

Upcoming Events

By Cathy Caldwell

Opportunities in-person and virtual

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Soil Erosion

• October 3, 2022
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Editor’s Note:  Guest author Dr. Linda K. Blum earned her BS degree in Forest Soils, her MS degree in Forest Soils Microbiology from Michigan Technological University, and completed her PhD in Agronomy at Cornell University in 1980. Her research focused on the interaction of nitrogen-fixing soil bacteria, pathogenic root-fungi, and protozoans in bean crops in developing countries. After joining the faculty at the University of Virginia in 1984, she continued to explore questions about plant-soil-microorganism interactions. Her passion for vegetable gardening is lifelong. Her first memory of gardening is planting tomatoes with her father when she was four years old. She became an Extension Master Gardener in spring 2021.  

Please Note:  The reference numbers contained in parentheses refer to the numbered citations at the end of the article.

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The soil beneath our feet is one of humanity’s most precious resources. Yet, humans are destroying this resource at rates faster than ever before in human history (1). Soil erosion was a major factor in the decline of past civilizations following deforestation in the Middle East, Greece, Rome, Mesoamerica, Norse Greenland, Easter Island, and North Africa (2, 3). Currently, soil erosion is a more pressing problem than at any time in history as human populations continue to increase at dramatic rates and desertification of formerly productive land continues at unprecedented rates. In the last 150 years, half the topsoil on the globe has been lost due to erosion (4). Global average rates of soil erosion are 5 to 7 US tons per acre per year (5), the equivalent of losing about 0.5 inches of soil per year from the surface of the World’s agricultural lands. This rate of loss is more rapid than the rate of soil formation, and therefore, poses a long-term threat to soils and the services they provide (2).

Erosion from cropland leads to soil degradation. Photo: USDA Natural Resources Conservation Service.

Evidence of Erosion Throughout the Landscape

Splash erosion. When a raindrop falls on bare soil, soil particles can be splashed up to three feet away. Photo: USDA NRCS.

Soil erosion is the physical process that wears away the soil surface by the action of water, wind, ice, and gravity. Erosion by water is the dominant mechanism causing erosion. When rain drops fall on soil, the droplets dislodge soil particles and splash them into the air. Splash erosion makes the soil particles vulnerable to water flowing across the surface of the land. (6). When soil particles are carried by water flowing across the surface of the soil, the erosion is called sheet erosion. As the water carrying the soil particles flows downhill, it concentrates into small channels called rills where the water velocity increases, and more soil particles are eroded from the surface in a process called rill erosion.

Rills are common, especially on bare land (1). Once rills have formed, substantial amounts of erosion may occur (7).  Rills can be further concentrated as water velocity increases and cuts deeper into the soil to form gullies. This is gully erosion. While gullies or channels are large (ordinary tillage cannot remove them), most erosion occurs as sheet and rill erosion (1). Rills and gullies or soil deposited at the base of steep slopes are classic indicators of soil erosion.

Rill erosion.  Photo:  USDA NRCS

Human Activities Increase Erosion

Some soil erosion takes place naturally without human activity. This type of erosion, termed geologic erosion, occurs slowly and is an important geological and soil-forming process (2). It is accelerated erosion, which occurs when human activities disturb the soil by harvesting lumber, grazing animals, and clearing land to grow crops, construct roads, and erect buildings, that results in unsustainable rates of soil erosion. In the US, only half the erosion is from agricultural activities; the other half is a result of road and building construction, including homes. Any human activity that exposes the soil surface has the potential to accelerate the rate of erosion over the geological rate; thus, rates of accelerated erosion in the US are 10 to 1000 times that of geologic erosion (1).

Erosion Decreases Environmental Quality

There is no more destructive soil process than human-induced soil erosion (1). Soil erosion decreases the ability of soil to support plant growth.  Erosion removes topsoil,  decreasing the depth of soil available for development of plant roots, reduces soil organic matter, decreasing the ability of soil to retain water and provide nutrients to plants, and destroys soil structure, increasing soil compaction which decreases soil-water retention and makes it more difficult for plant roots to penetrate the soil. Impacts of soil erosion are not limited to soil loss. The eroded material, called sediment, is carried to waterbodies (streams, lakes, reservoirs, and coastal waters) and leads to water quality problems such as increase in nutrients, algal blooms, low oxygen, and fish kills (8).

 Conditions Influencing Erosion

In 1978, scientists developed the Universal Soil Loss Equation (USLE) to quantify sheet and rill soil-erosion (9).  The factors included in this equation are those that have the greatest impact on erosion and focus on three groups of conditions, including climate (especially rainfall characteristics), soil properties (topography and the ability of soil to absorb rainfall), and land management (vegetative cover and erosion control practices).  Let’s examine these factors in a little more detail.

Climate: The driving force for sheet and rill erosion is the frequency, duration, and intensity of rainfall, especially the intensity of rainfall (1). Intensity is of great importance because intense rain has large raindrops which are more able to detach particles from the soil, causing rainwater and soil particles to flow across the soil surface. Gentle rain causes little erosion; heavy downpours can cause severe erosion. Temperature is important because it influences the type of precipitation. There is no erosion when it snows, when the ground is covered with snow, or when the soil is frozen (snow melt is another story!). Rainfall varies dramatically from place-to-place and from year-to-year and so does the potential for soil erosion.

Soil Properties: Soils are not equally susceptible to erosion. When soils are able to absorb rainfall rapidly, less water will be available to flow across the soil surface (6). When water stays on the soil surface, raindrops are more likely to splash and detach soil particles. Well-aggregated soils (soil particles held together primarily by fungi and organic matter) resist being broken apart by raindrops and have a higher capacity to absorb water than soils that are not well-aggregated. Soils with a sandy texture generally absorb water rapidly; for example, beach sand. Soils high in clay are slow to absorb water, but here in central Virginia the soils are high in iron and aluminum which form highly stable aggregates that resist erosive processes (6). Soils that resist erosion are high in organic matter (increases water absorption), high in most types of clays (but once eroded are easily transported), or contain a high proportion of large sand grains. Soils that are most susceptible to erosion have high proportions of fine sands and silts, low organic matter content, and/or shrink-swell clays (found throughout Virginia). Gravel and gravel-sand mixtures are least erodible. 

Soil Topography: The two primary components of topography that influence soil erosion are the length and the steepness of the soil surface slope (1). The longer and steeper the slope, the more opportunity there is for water to detach soil particles. Steep slopes (33% – 50%) are especially susceptible to erosion. Another factor to consider is the orientation or aspect of the slope. South-facing slopes dry-out more rapidly than north-facing slopes, and therefore, have greater capacity to absorb water; however, slope steepness has the greatest impact on soil erosion. 

Vegetative Cover:  The presence and type of vegetation play a major role in influencing soil erosion (6). Vegetation shields the soil surface from raindrop impact, reducing splash erosion (10). Plant root systems hold soil particles in place and slow water flow over the soil surface (11). Plants add organic matter to the soil, which increases the soil’s capacity to absorb water (12, 13) and removes water from the soil between rainfalls through evapotranspiration (evaporation from plant surfaces and water moved through the plant conductive tissues to the atmosphere) (14). 

Effect of cover on soil erosion (top row of jugs) and water infiltration into the soil (bottom row of jugs) in a rain simulator. Soil cover treatments from left to right: pine forest floor litter, over-seeded hayfield, grazed pasture, bare ground, and small grain cover-crop. Less water infiltrates into the soil as runoff and soil erosion increase. Photo: Jennifer T. Miller, courtesy UGA Extension Jeff Davis County.

Not all plants provide similar erosion control benefits (9, 15). Undisturbed forests and dense grass provide the best protection. Forage crops (legumes and grasses), which home gardeners may grow as a cover crop, are effective because the plants grow as a dense cover. Crops grown in rows (beans, corn, tomatoes, potatoes, etc.) provide little protection until the plants are sufficiently large to cover the soil (1). 

Solving the Soil Erosion Problem

“Combating soil erosion is everybody’s business” (1).  If water runs over the surface of the soil, erosion will occur. However, there are ways to slow erosion and derive the benefits of erosion control. Benefits may include improved plant growth in gardens and lawns, cleaner water and air, and higher property values.

In general, there are two steps that homeowners and land managers can use to limit erosion from their property: keep the soil covered and promote on-site infiltration (water absorption into the soil) to slow the rate of water flow. 

• Keep the soil covered with vegetation: plant vegetation that forms a dense canopy to limit splash erosion and extensive root systems to hold the soil in place. Perennial plants have more extensive root systems than annuals and are better for erosion prevention. Plant cover crops during the off-season for vegetables. Take advantage of between growing-season cover-crops and use no-till approaches especially for row crops. Cover crops are a very effective way to reduce soil erosion between perennial plants and fruit trees while providing weed control.  
• Keep the soil covered with straw or compost mulch: both are effective at reducing soil erosion (16, 17). When using mulch, it is important to inspect and replace after each rainfall. Even in the absence of rain, it is recommended that mulches be inspected at least weekly to be sure these materials are still in place.  
• Promote infiltration and slow flow: Allow water to collect in rain gardens and infiltrate slowly into the soil between rain events (18).
• Promote infiltration and slow flow: Collect water from gutters by installing rain barrels at downspouts to slow water flow from the property and for watering plants during periods between rainfall. To maximize the amount of water collected, keep building gutters free of debris and downspouts connected (19).
• Promote infiltration and slow flow: Reduce impervious surfaces by replacing sidewalks and driveways with steppingstones or pervious materials. Construct pathways across, rather than parallel with, slopes (20).

Make Reducing Erosion Your Business

Maintaining productive gardens and ecologically resilient landscapes depends upon soil quality – the soil’s ability to provide the water, nutrients, and rooting-medium to support plant growth, nutrient cycling, and organic carbon storage. Conversely, soil quality depends upon vegetative cover. Soil erosion leads to soil degradation and the ability of the soil to store organic carbon and to provide water, nutrients, and physical support to plants. Where soil is disturbed and remains exposed after vegetation removal, soil erosion is enhanced, soils are degraded, and plant health is reduced. Vegetation with dense canopies and extensive root systems lessens soil erosion and promotes soil quality. Wise plant choices and management practices for home gardens and lawns can reduce soil erosion and promote soil quality; plants are more productive with lower fertilizer application needs, and disease- and pest-control requirements. The environmental impact of erosion control actions can have beneficial impacts that reach beyond individual properties and result in improved water and air quality in the local water- and air-shed. Let’s all make it our business to reduce soil erosion in our gardens, lawns, and woodlots.

Featured Photo:  Gully erosion. Photo:  USDA Natural Resources Conservation Service Oregon, CC BY-ND 2.0

Citations

1.  Brady, N.C. and R.R. Weil. 2004. Elements of the Nature and Properties of Soils, 2nd Edition. Pearson Education, Inc., Upper Saddle River, NJ. p. 606.

2. Montgomery, D. R. 2007. Soil erosion and agricultural sustainability. PNAS 104(33):13268-13272. 

3. Diamond, J. 2005. Collapse: How Societies Choose to Fail or Survive. Viking Press, New York City, NY. p. 592 

4. www.worldwildlife.org/soil-erosion-and-degradationhttps://www.worldwildlife.org/threats/soil-erosion-and-degradation; accessed 7-19-2022

5. den Biggelaar, C., R. Lal, K. Wiebe, H. Eswaran, V. Breneman, and P. Reich.  2003. The global impact of soil erosion on productivity: II. Effects on crop yields and production over time. Advances in Agronomy 81:49-95. 

6. Virginia Department of Conservation and Recreation Division of Soil and Water Conservation. 1992. Virginia Erosion and Sediment Control Handbook, 3rd Edition. Virginia Department of Environmental Quality, Richmond, VA. p. 834. https://assets.vbt.io/public/files/6975/VA_Resources_Construction/Virginia_DEQ_Erosion_and_Sediment_Control_Handbook.pdf;  accessed 7-22-202

7. Gilley, J.E. 2005. Erosion: Water-Induced. In: Encyclopedia of the Soils in the Environment, (eds.) Hillel, D. and J.L. Hatfield. Elsevier Science Publishing, Amsterdam, The Netherlands. p. 2200.

8.https://static1.squarespace.com/static/5201a163e4b01f15d7f763c6/t/520af5b8e4b033742444e254/1376449976308/erosion_control_homeowner_guide.pdf; accessed 7-22-2022.

9. Wischmeier, W.J. and D.D. Smith. 1978. Predicting rainfall Erosion Loss – A Guide to Conservation Planning. Agricultural Handbook no. 537. Washington, D.C., USA

10. Bochet E., J.L. Rubio, and J. Poesen. 1998. Relative efficiency of three representative matorral species in reducing water erosion at the microscale in a semi-arid climate, Geomorphology 23: 139–150.

11. Ola, A., I. C. Dodd, and J. N. Quinton. 2015. Can we manipulate root system architecture to control soil erosion? SOIL 1:603–612.  https://doi.org/10.5194/soil-1-603-2015;  accessed 8-23-2022.

12. Wainwright J. 1996. Infiltration, runoff and erosion characteristics of agricultural land in extreme storm event, SE France. Catena 26:27–47.

13. Ziegler A.D. and T.W. Giambelluca. 1998. Influence of revegetation efforts on hydrologic response and erosion, Kaho’Olawe Island, Hawaii, Land Degradation and Development 9:189–206.

14. Zuazo, V.H.D. and C.R.R. Pleguezuelo. 2009. Soil-erosion and runoff prevention by plant covers: A review. In: Lichtfouse, E., Navarrete, M., Debaeke, P., Véronique, S., Alberola, C. (eds) Sustainable Agriculture. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-2666-8_48

15. Schwab, G.O., D.D. Fangmeier, and W.J. Elliot. 1995. Soil and Water management Systems, 4th ed. Wiley. New York, NY, USA. 384p. ISBN: 978-0-471-10973-0

16.https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/mipmctn11904.pdf; accessed 8-23-2022

17. https://extension.uga.edu/publications/detail.html?number=B1200&title=Compost%20Utilization%20for%20Erosion%20Control); accessed 8-22-2022

18. ; accessed 8-20-2022.

19. https://canr.udel.edu/wp-content/uploads/sites/16/2018/03/12024201/Harvesting_Water.pdf; accessed 8-20-2022

20. https://canr.udel.edu/wp-content/uploads/sites/16/2018/03/12024201/Permeable_Impermeable_Surfaces.pdf; accessed 8-20-2022

 

 

 

 

 

 

 

 

How to Grow Garlic

• October 3, 2022
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• 1 Comment

From the Editor:  We are delighted to be able to reprint this article by Cleve Campbell, the originator and driving force of The Garden Shed in its early years. It’s been seven years since its original publication in October 2015.  Last month’s issue featured an article about the vegetable garden of Fern and Cleve Campbell, so it seemed particularly apropos. Links for sources have been updated.

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One of the easiest crops I have every tried to grow is garlic.  Why?  Well, first of all, the critters (rabbits, deer, groundhogs, and squirrels) avoid it.  Even insects generally ignore it.  Plus,  garlic has few disease and pest problems. Aside from a little weeding, garlic requires very little maintenance.  And if your passion is organic gardening, it doesn’t get any easier than growing organic garlic.

One of the joys of growing garlic is that it is out-of-sync with most other vegetable crops; instead of contributing to the spring planting workload, garlic is planted in the fall. The taste of fresh homegrown garlic reminds me of the difference between a homegrown tomato and a tomato from the supermarket. And just like those supermarket tomatoes, the garlic you find in the supermarket is grown for shelf life, not taste. Without a doubt, garlic works miracles in the kitchen when added to soups, stews, tomato sauces, salsas, pickles, salads, salad dressings, marinades, mashed potatoes, seafood — hey, clams with butter and garlic!  WOW! One has to search hard for a modern recipe that has onion but does not include garlic. A roasted bulb with a drizzle of olive oil and a pinch of salt turns into butter when you spread it over a slice of warm bread. Most cooks find it indispensable in the kitchen, and these days it is rare to find a recipe that does not call for garlic.  In fact, a diligent researcher can even find a dessert recipe featuring garlic: “Roasted Garlic Chocolate Chip Cookies”. YUMMMM!!!

A Brief History of Garlic

Garlic is believed to have originated in the mountains of Central Asia, in the present-day counties of Kazakhstan, Uzbekistan, and Turkmenistan. Today garlic is found wild in Siberia and the slopes of the Ural Mountains.  Garlic has been cultivated for thousands of years.  Egyptian and Indian cultures refer to garlic use dating back 5000 years. Detailed models of garlic bulbs were unearthed in the tomb of El Mahasna, in Egypt, dating back to 3750 BC. The Bible suggests the Israelites may have developed a fondness for garlic around 1500 BC:  “We remember the fish, which we did eat in Egypt, the cucumbers, and the melons and the leeks and the onions and the garlick.” Numbers 11:5.

Today garlic ranks second only to the onion as the second-most important Allium crop in the world. A plant, rich in history, that can fight disease, thin blood, reduce cholesterol, season a variety of foods, repel insects and vampires and is celebrated annually by thousands of devotees at numerous garlic festivals throughout the country deserves a spot in the vegetable garden.

Types of Garlic

There are hundreds of varieties of garlic, but generally, they are categorized into two different subspecies or groups: hardneck (Allium sativum var. ophioscorodon) and softneck (Allium sativum var. sativum). Each group has several distinct varieties and cultivars.

Hardneck Garlic

In the spring, hardneck garlic produces a false flower stalk called a scape.  Hardneck garlic is also known as “Top Setting Garlic” because it produces clusters of small bulbs (“bulbils”) at the end of the scape after the mostly sterile flowers bloom.  Some garlic experts believe that hardneck garlic has more flavor than the more domesticated softneck garlic, and it is often referred to as gourmet garlic. Hardneck garlic does not store as well as softneck garlic.

There are 3 subcategories of hardneck garlic:

•  Rocambole: the most widely-grown of the hardnecks, producing large cloves that are easy to peel. This is the only garlic that sends up a double scape loop.  Killarney Red, Spanish Roja, German Giant and German Red are examples of Rocambole varieties.
• Porcelain: This type displays satiny white wrappers and has large cloves, but typically only four cloves. Has the longest shelflife of the hardnecks. After storing, they can be hotter than Rocambole. Porcelain varieties include China Dawn, Georgian Crystal, German White and Music.
• 

  Purple stripe garlic

  Purple Stripe: named for the bright streaks and blotches on both bulb and clove skins. Purple Stripe garlic is milder and stores longer than the Rocambole types. Varieties include Chesnok Red, Persian Star, Siberian and Celeste.

 

Softneck Garlic:

Softneck is probably the kind of garlic that people think of when garlic is mentioned.  Commercially grown because of its long storage attribute, softneck garlic is the kind usually found in supermarkets and in garlic powder. The skin on softneck garlic is tight on the clove, making it hard to peel, but protecting it and keeping it fresher longer. Softneck garlic is productive in a wide range of climates and soils, out-performs hardnecks in warmer climates, and is usually easier to grow.

There are two major subcategories of softneck garlic:

• Artichoke: named for the fact that the cloves overlap, similar to the artichoke. They have a long shelflife but the taste can be hot.  Artichoke varieties are easiest to grow and seem to be less fussy about growing conditions than other varieties and do very well in warm winter locations.  Artichoke varieties include:
  

  Braided garlic. Photo: Andrei!, CC BY-SA 2.0

  Italian White, Inchelium Red, Polish White and Susanville.

• Silverskin: These are the longest lasting of the garlics and usually the last harvested.  They can be very, very hot. This is considered the very best for braiding. Silverskin variety generally grow in most areas of the United States, and if harvested and cured properly, can be stored up to 10 months. Silverskin varieties include Chet’s Italian Red, Nootka Rose and Sicilian Silver.

 

 

Central Virginia is in a transition zone, and both hardneck and softneck garlic do reasonably well in our area. The hardneck varieties that have performed well for me are China Dawn and Red Killarney. Softneck varieties that have performed well in my garden are: Susanville, Polish White, and Sicilian.

 

Elephant Garlic:

Elephant Garlic is not true garlic; it belongs to the leek (Allium ampeloprasum) family. In recent years elephant garlic has become popular due to the huge size of its bulbs and its milder flavor.

When to Plant Garlic

Garlic is planted in the fall. In our area, mid-October is the recommended time for planting. Garlic requires a cold treatment period (vernalization) of 32-50° F. for about two months to induce bulbing. Garlic can be planted in the spring, but it should be refrigerated first for several weeks. However, smaller bulbs can be expected if spring-planted, because of the limited growing period.

Do NOT plant garlic that you purchased from the grocery store, as they may be diseased and are often unreliable because they may have been treated with an anti-sprouting chemical. There are numerous online retailers that sell organic garlic for planting.

Site and Cultural Requirements:

Select a sunny or partially shady location to plant your garlic. Good soil drainage is essential for a good garlic crop. One way to improve the drainage is by creating a raised bed before planting.  The soil pH should be between 6.5 and 7.0. A  light, well-drained soil also reduces the number of irregularly-shaped bulbs. Adding compost or well-rotted manure and mixing it thoroughly can improve heavy clay.

Garlic is a heavy nitrogen feeder; the recommended rate of application is 30 to 60 pounds per acre. Downsizing that number to a manageable garden space of 100 square feet equates to 0.07 to 0.14 pounds of nitrogen per 100 square feet. Doing the math for the standard 10-10-10 fertilizer, that would require approximately 0.68  to 1.37 pounds of standard fertilizer. An alternative organic fertilizer of cottonseed meal (6-2-2) would require approximately 1.15  to 2.3 pounds of cottonseed meal. Because nitrogen is “unstable” and tends to leach, one of the recommendations when using standard fertilizer is to apply a top dressing in the late winter (February) and again in March. Cottonseed meal is a slow-release fertilizer, so it may be applied when the garlic is planted and followed up with a top dressing again in February.

Garlic is also a heavy user of phosphate and potassium, and these elements should be added, as with other crops, only in accordance with a soil test. A free Soil Test Kit is available at your local Virginia Cooperative Extension Office.

Planting

In general, garlic, like potatoes, multiplies by vegetative reproduction rather than by sexual reproduction (seeds). Individual garlic cloves are planted and each clove then produces a cloned bulb, having the same genetic make-up as the original parent.

The planting process begins by carefully separating the cloves,  just before planting, removing the outer layer of papery skin, and then removing the cloves from the basal plate (the flat base where the roots originated). The papery skin on the individual cloves can be left intact. Select only healthy, firm, unblemished cloves for planting, and aim to use the largest cloves available.  In general, the larger cloves yield the largest garlic bulbs. Don’t disregard the small cloves — they can be used in the kitchen, or frozen for future culinary uses.

Plant the cloves 1-2 inches deep with the pointed end up. Space the cloves 6-8 inches apart. Over-crowding the garlic may result in smaller bulbs. Each garlic clove will yield one bulb. When the planting is complete, add about 1-2 inches of compost or leaf mold  or straw over the planting area to prevent moisture loss. Mulching your garlic bed tends to increase your yield and the size of your bulbs.

 

Maintenance

Garlic is a poor competitor, so good weed-control is essential. In general, fall and winter weed problems are minimal, though spring and summer will bring more weeds.  Applying a couple of inches of mulch such as leaf mold or clean straw can help control the weeds. If weeding is required, use caution to avoid damaging the bulbs and roots.

If you are growing hardneck garlic, you may want to consider removing the scape when it begins to uncoil and straighten out. Removing the scape allows the plant to direct its energy toward bulb development rather than bulbils development. Depending on the cultivar, removing the scape can result in 25-30 percent or more in bulb weight.

Garlic requires about an inch of water a week (similar to other garden vegetables), during the spring growing season.  Stop watering the plants about a month before harvest  — when the leaves begin to yellow —  to keep the papery skin dry and prevent the bulbs from rotting or splitting.

During late spring and early summer garlic can be susceptible to the same insects and diseases as onions and leeks — thrips and various bulb rots. However, garlic is relatively carefree when grown in a well-drained organic soil (5-10% organic matter), with good air circulation, and if you stick to a 2-3 year rotation cycle with other vegetables.

Harvesting

Fall-planted garlic grows roots soon after planting, but top growth does not occur until the following spring, and the garlic bulbs are usually mature by early to mid-summer.

Garlic can be harvested in three forms —  scapes, green, or bulbs — each of which is based on timing.  In the spring, hardneck garlic produces a scape. Most gardeners prefer to remove the scape to allow the plant to focus its energy on the bulb. The scapes can be cut off shortly after the flower stalk curls. Harvested scapes can be used in cooking or salad, providing garlic-tasting greens similar to scallions. When garlic scapes are harvested this way, before full maturity, they are referred to as green garlic. Green garlic can be used like green onions in salads or cooking.

Knowing when to harvest garlic bulbs is like knowing when to sell a stock in the stock market. At the end of the growing season — early summer — the bulbs are growing at their fastest rate. If the crop is harvested too early, the bulbs may be undersized, but if harvested too late, the thin wrapper that holds the bulb begins to deteriorate and the bulb itself begins to fall apart. Naturally, most gardeners are greedy, myself included, and want the biggest garlic bulbs possible, leading to that temptation to wait too long.

Bulbs are ready to harvest when the leaves begin to yellow or brown and fall over, but there are still 50% green leaves on the plant. Green leaves indicate that the bulbs are still intact and have not begun to break apart. If you wait until all the leaves have turned brown and fallen over, you have waited too long. Before harvesting, I usually dig up a few “test bulbs”  to check the wrappers.  If they are in good shape, I wait a few more days and dig a few more.

When you pull the trigger and begin to harvest, carefully loosen the soil around the bulb to minimize damage. The preference is to dig up the garlic bulb rather than pulling it out. I am often amazed at the depth of the garlic bulb and the number of roots that have developed. Shake off the excess soil, keeping the wrapper intact. With more of the wrapper in place, the garlic will store longer. Do not wash the bulbs as that may encourage the growth of fungus and reduce the shelf life of the bulb.

Curing and Storing

Curing the harvested garlic will extend the shelf life of the bulb and strengthen its flavor. To cure the garlic, tie into bunches and hang in a shady, cool, dry, and well-ventilated location for 4 to 6 weeks. I often use a fan to increase the ventilation.

Once the bulbs have been cured, I sort the garlic; I save the largest bulbs to be planted the following fall, and the remainder I store in a dark, well-ventilated area. I use a homemade screen that hangs in the basement and it works well.

Garlic is a seed savers’ delight.  There’s no need to worry about cross-pollination because what you save  is a clone of the parent plant. In addition, garlic adapts to its environment, so the more seasons you plant your saved garlic in the same microclimate, the better it performs. I have noticed that after about the fourth year, the garlic appears to become happy with its new home, and I am rewarded with larger bulbs.

What’s not to like about growing your own garlic? It will be fresher and tastier than the garlic found in the supermarket, and you’ll have hundreds of varieties to choose from — way more than what is available in the supermarket. Pests mostly leave it alone, and other than a little weeding and occasional watering, it’s maintenance-free. On top of all that, because garlic adapts to local conditions, you’ll have the reward of being able to save your own garlic and plant it year after year, knowing that each year your crop will get a little better.

Thanks for joining us in The Garden Shed this month. We hope you will visit again next month.

Featured Photo:  Cleve Campbell

Sources:

“Time to Plant Garlic,” VA Tech Horticulture (Tony Bratsch, 2003)

“Roasted Garlic Chocolate Chip Cookies Recipe,” Mother Earth Living (July-August, 2004)  http://www.motherearthliving.com/food-and-recipes/summer-recipes/roasted-garlic-chocolate-chip-cookies-recipe-zmoz04jazmel.aspx

“Glorious Garlic, Herb of the Year 2004,” Virginia Coop.Ext., vtechworks.lib.vt.edu

“The origins and distribution of garlic: How many garlics are there?”  United States Department of Agriculture, http://www.ars.usda.gov/Research/docs.htm?docid=5232

Garlic – An Herb Society of America Guide, www.herbsociety.org (The Herb Society of America, 2004, 2006)

“Garlic Productivity and Profitability as Affected by Seed Clove Size, Planting Density and Planting Method,” HortScience, Vol. 39, No. 6, hortsci.ashspublications.org (Oct. 2004)

“No-till Organic Culture of Garlic Utilizing Different Cover Crop Residues and Straw Mulch for Over-wintering Protection Under Two Seasonal Levels of Organic Nitrogen,”  Virginia Cooperative Extension, Pub.No. 2906-1389 vtechworks.lib.vt.edu (2006)

“Growing Garlic,” University of Vermont Extension’s Vermont Vegetable and Berry Program, http://www.uvm.edu/vtvegandberry/factsheets/Garlic.html

“Growing Garlic,” NC State Ext/Lee County

“Growing a Successful Garlic Crop,” https://wilkes.ces.ncsu.edu/2020/10/growing-a-successful-garlic-crop/

“Soil Sampling for the Home Gardner,” Virginia Cooperative Extension, Publication 452-129,  http://pubs.ext.vt.edu/452/452-129/452-129.html

 

Upcoming Events

• October 3, 2022
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Blue Ridge Prism Fall Invasive Plant Workshops

Wednesday, October 12 @ 1:00 — 3:00 pm

Blue Ridge PRISM’s 2022 Workshops are a blend of two virtual sessions and an optional in-person field session. Register for the virtual sessions or a field session or both!

Session 1 (virtual) : Introduction to Invasive Plants and Identification, October 12, 2022, $10

Register here.

Session 2 (virtual): Management & Control of Invasive Plants in the Fall

October 13, 2022, $10

Register here.

Invasive Plant In-person Field Session

Sat.October 15, 2022

12:30-3:30 pm

Pen Park, Charlottesville, Va.

This fall workshop will take place on Saturday Oct 15th from 12:30 – 3:30 pm at Pen Park in Charlottesville, Va. and will include an invasive plant identification walk and in-person instruction. Space is limited to 25 participants. Registration fee is $25.

Coming up in November . . .

Garden Basics: Why and How to Reduce Chemical Use in Your Yard and Garden

The Ornamental Garden in October

• October 2, 2022
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• 1 Comment

October rivals anything that spring has to offer in terms of beauty, color and interest in the ornamental garden.  Masses of late blooming perennials, shrubs with brightly hued berries, and the vibrant fall foliage on many trees and shrubs collectively provide a truly glorious gardening experience.  Meanwhile, this month is a particularly busy time for gardeners.  So let’s get started on that “to do” list.

PLANT, DIVIDE, AND TRANSPLANT

• Plant spring flowering bulbs now that soil temperatures are dropping into the 60s or below. For a succession of color throughout spring, plant a variety of early, mid- and late season bulbs starting with the earliest snowdrops and ending with late blooming tulips and alliums.  Tip: Some gardeners have a reaction similar to contact dermatitis when handling tulip, daffodil, or hyacinth bulbs.  As a precaution, wear gardening gloves when handling bulbs or wash your hands with cool water and soap immediately after planting.
• Plant cool-season annuals such as snapdragon, calendula, Iceland poppy, sweet alyssum, stock, and larkspur. Seeds sown in fall of cool-season annuals will bloom about two weeks earlier than spring-planted seeds.  Transplants of other cool-season annuals, such as pansies and violas, are generally easy to find in local garden centers.  For best results, they need to be well established in the soil before freezing winter weather sets in.
• Divide overcrowded perennials such as daylilies, yarrow, coreopsis, shasta daisy, and Stachys (lambs’ ears). Water them in well so that they become well established before winter but hold off on mulching them until after the first hard frost to help prevent frost heaving.
• Plant deciduous trees and shrubs before the ground freezes and keep them well watered until they become dormant.   Think about planting trees and shrubs that offer multi-seasonal interest. A few suggested trees to consider include maple (Acer), black gum (Nyssa sylvatica), dogwood (Cornus), or sourwood (Oxydendrum arboretum).   Some suggested shrubs for multi-seasonal interest include Virginia sweetspire (Itea virginica), oakleaf hydrangea (Hydrangea quercifolia), fothergilla (Fothergilla gardenii), blueberry (Vaccinium spp.), red-twig dogwood (Cornus spp.), or spicebush (Lindera benzoin).   For tips on how to prepare the planting site and care for trees and shrubs while they are becoming established, see Virginia Cooperative Extension (VCE) Publication 430-295, Tree and Shrub Planting Guidelines.  Also, check the National Weather Service’s Climate Prediction Center for long-term forecasts so that you can time the planting before a rain is predicted to fall.

TACKLE GENERAL FALL GARDEN CLEAN UP TASKS

• Clean up all flower beds. Remove all weeds, twigs, spent annuals, and other debris from flower beds.   However, if you’re a bird lover, leave some seed-bearing perennials in place. Echinacea (coneflower), Rudbeckia (black-eyed Susan), ornamental grasses, and other plants, such as sunflowers, will provide food for the birds this winter as well as sanctuary for overwintering beneficial insects.  Wait until late winter or early spring to cut them back before new foliage emerges.
• Not sure which perennials to cut back and which to leave standing over the winter? Some plants should be cut back for aesthetics and to prevent the overwintering of pests and diseases.  The best time to do this is after a couple of killing frosts.  If the weather continues to stay warm in October and the plants are still producing flowers, this task may need to wait until November.  Here’s a brief selected listing of perennials to cut back in autumn and why:
  • Achillea (yarrow) – Cut back to induce new basal growth, which helps protect the plant crown in winter.
  • Aquilegia (columbine) – Cut back to control leaf miners.
  • Baptisia (false indigo) – Unless you like the dark seed pods, cut the plant back for aesthetics. The foliage turns black after frost and is unattractive.
  • Bearded Iris – Cut back to prevent overwintering fungal disease and iris borers.
  • Corydalis – Cut back to contain the plant and to keep it from spreading.
  • Crocosmia – Cut back for aesthetics.
  • Hemerocallis (daylily) – Unless you have an evergreen variety, remove dead foliage and dried flower stalks for aesthetics and to help contain daylily rust (fungal disease).
  • Hosta – Cut back for aesthetics. Foliage turns to a mushy mess with the first hard frost.
  • Iris domestica (blackberry lily) – May be cut back in either spring or fall. Leave standing until spring if you want the interesting seed heads to add interest to the winter landscape.   Cut back now if you want to avoid harboring overwintering borers or if you want to keep the seeds under control.
  • Monarda (beebalm) – Cut back to control the spread of powdery mildew.
  • Phlox paniculata (garden phlox) – Cut back to prevent the spread of fungal diseases and to prevent the plant from dropping seeds in the garden.
• While many perennials need to be cut back in the fall for aesthetics and pest/disease control, there are advantages to leaving some perennials in place until late winter or early spring before the new foliage emerges. So it’s OK, in fact desirable, to leave some dormant foliage and stems in place over winter. A major reason is that the old foliage helps protect the crown of the plant over the winter months. Another good reason is that many beneficial insects overwinter in the dead stems and foliage as eggs or pupae and then hatch out in the spring. Here’s a brief selected listing of perennials that may be left standing and why:
  • Agastache — The stems help protect the crown of the plant over winter and also provide habitat for overwintering beneficial insects.
  • Amsonia – The foliage helps protect the crown of the plant during the winter. Also, fallen leaves often catch in the plant’s standing stalks and provide extra protection to the crown.
  • Aster novae-angliae (New England aster) – The foliage and stems on this late-blooming perennial help protect the crown and add texture and interest in the winter landscape.
  • Bergenia (pigsqueak) – The evergreen leaves turn shades of purple and deep red and provide interest in the winter garden.
  • Chrysanthemum – The foliage and stems help protect the crown over winter.
  • Echinacea – The seedheads provide food for birds as well as texture and interest in the winter landscape.
  • Gaillardia (blanket flower) – This plant may be cut back in either spring or fall. The seedheads provide food for the birds over winter.  If you don’t want the plant to re-seed, cut back in autumn.
  • Helleborus – The foliage remains green over winter, which adds texture and interest to the garden. However, it will look unsightly by late winter, at which point it should be carefully cut back before the new spring growth emerges.
  • Tall Sedum – The browned seedheads look attractive in the winter and the hollow stems provide overwintering sites for beneficial insects.
• Dig up the bulbs or roots of tender perennials such as canna, dahlia, caladium, Alocasia (elephant’s ear), tuberose, and gladiolus and prepare them for winter storage. These bulbs are either not hardy to USDA Zone 7 or are only marginally hardy. This task is easier if you wait until after a light frost blackens the foliage.  Cut off all the foliage, then carefully dig up the roots so that you don’t damage them.  Inspect them and discard any that appear diseased or soft.  Allow the roots to dry thoroughly, clean off soil, and pack loosely in peat moss or vermiculite in open baskets or cardboard boxes.  Store in a cool, dry, dark, frost-free location over the winter.  Don’t forget to label the bulbs so that you can easily identify them next spring.
• Mark where late emerging perennials are planted so that you don’t damage them next spring when you begin working in your flower beds. Asclepias (milkweed), Platycodon (balloon flower), Baptisia (false indigo), and some ferns are examples of late emerging perennials.
• Bag all diseased foliage and stems from peonies, garden phlox, or roses and dispose of the debris in the trash. Do not add it to the compost pile.  This will reduce the overwintering of botrytis blight, mildew, and other fungal spores.
• Remove cool-season weeds, such as chickweed, dandelion, wild onion, plantain, and white clover. A few minutes spent pulling these weeds from flowerbeds now will save you many hours of work next spring.
• Protect water features from the accumulation of falling leaves and other debris. Spread netting over the water feature and secure it to keep the leaves out of the water. Remove the leaves from the netting as they accumulate.
• Shred or chop fallen leaves and compost them or save them to use as mulch on next year’s garden. If you’re new to composting, check out VCE Publication 426-703, Making Compost From Yard Waste. For additional information on mulching and composting leaves, see The Garden Shed’s October 2018 Tasks and Tips for the Ornamental Garden in October.
• Have a soil test done this fall if you haven’t had one done in the past two or three years. Soil amendments, such as lime, manure, compost, and chopped leaves, are best added to flower beds in the fall.  But don’t amend until after you get the results of the soil test. For additional information on soil testing, see VCE Publication 452-129, Soil Sampling for the Home Gardener.
• Leave seed heads in place for annuals that you want to self-seed or just scatter the mature seeds where you want them yourself. Some annuals and biennials that reseed themselves include cleome, cockscomb, cosmos, foxglove, hollyhock, larkspur, money plant, sweet William, forget-me-not, Shirley poppy, zinnia, four-o-clock, marigold, vinca (Madagascar periwinkle), and impatiens.
• Take preemptive action to prevent deer damage to the bark or branches of young or newly planted trees and shrubs. In fall and winter, male deer rub or scrape against young trees for two reasons: (1) to rub the summer velvet from their horns and (2) to mark their territory as a way to attract female deer and warn other male deer away. Wrap vulnerable tree trunks with a physical barrier such as wire or plastic mesh tree guards, chicken wire, or woven wire fencing. This will protect the trees while allowing them room to grow.

MANAGE AUTUMN INSECT PESTS

Irises are susceptible to a variety of pests and diseases.  One of the most annoying is the iris borer, which is the larvae of the brownish-looking nocturnal Miller Moth (Macronoctua onusta).  The moth lays its eggs on old iris leaves and flower stalks in autumn.  The larvae hatch in late spring and tunnel into the leaves on their way down to the rhizome.  The damage they cause makes the rhizome susceptible to bacterial soft rot.  Iris borer eggs that overwinter on dead foliage are the source of infestation each spring.  To break the life cycle of this pest, remove dead leaves from rhizomes in autumn to prevent any eggs from surviving over the winter months.

Inspect your evergreen trees and shrubs for bagworms.  Bagworm eggs overwinter on evergreens such as junipers, spruce, hemlock, and arborvitae as well as many other trees.  Pick off and burn any egg cases that you find. This may be done from fall until spring. See VCE Publication ENTO-351NP on Bagworm for additional information.

PREVENT UNINVITED WINTER HOUSE GUESTS 

Around mid-October, the adult Lady Beetle (or Ladybugs as they are more commonly known) begins moving out of the garden and into nooks and crannies under tree bark, leaves, or other sheltered spots that will afford them protection from winter’s cold weather.  As they search for winter lodgings in earnest, they often enter our homes through tiny cracks around windows, doors, attic vents, or any other opening available to them.

The Brown Marmorated Stink Bug is another insect that often tries to overwinter in your home. Fortunately, the stink bug population seems to have dissipated somewhat over the past few years.  However, if you see them gathering on the south or west-facing side of your house, chances are very good that they will try to seek entry into your home for the winter.

Insects aren’t the only creatures seeking a warm place to spend the winter.  Rodents often look for entry points into the home.  To prevent access, seal all potential entry points.  Leaving the garage door up is an open invitation to a mouse or rat.  Make sure there’s no food available to attract them such as grass seed, bird seed, and seeds that you’ve saved from your garden.

ACCLIMATE HOUSEPLANTS

If you didn’t bring your houseplants indoors at the end of September, definitely get them indoors this month.  The longer they stay outside, the harder the transition to the indoors will be for them.   Once they are indoors, keep a close watch on them for spiders, spider mites, white fly, scale, mealy bug, and other unwanted hitch hikers.  These pests may not show up for days or even weeks after you’ve moved the plants indoors.

Houseplants may go through a period of adjustment to lower light levels.  If they are getting sufficient water but dropping leaves, they may not be getting enough light.  If that’s the case, try relocating them to a brighter location.

ENJOY THE AUTUMN LANDSCAPE AND PONDER WHY LEAVES CHANGE COLOR

As you work on your October gardening tasks, take time out to enjoy the view. As the days have shortened and temperatures cooled, the vivid colors of autumn have transformed the landscape. The transformation starts in the cooler, higher elevations and gradually spreads to the warmer, lower-lying valleys. Meanwhile, the veins that transport fluids into and out of leaves gradually close off at the base of each leaf.  The clogged veins trap sugars in the leaf, which promotes the production of anthocyanins.

Three types of pigments are involved in autumn color:

• Chlorophyll, which gives leaves their green color, is present in the chloroplasts of leaf cells throughout the entire growing season.
• Carotenoids, which produce yellow, orange and brown colors, are also present in the chloroplasts of leaf cells throughout the growing season but are masked by chlorophyll. Once the leaves stop producing chlorophyll, the carotenoid pigments become visible.
• Anthocyanins, which produce reds, pinks, and purples, are typically not present during the growing season. Anthocyanins are only produced in the fall and are manufactured from the sugars that are trapped in the leaves. They are water soluble and appear in the watery liquid of leaf cells.  Their purpose is to protect leaves from being eaten or from getting sunburned.

Many of us are puzzled by the fact that fall colors are vibrant some years and subdued in other years.   The intensity of color is influenced by temperature, sunlight, and soil moisture levels before and during the time chlorophyll is dwindling in the leaves.  The most brilliant autumn colors are generally produced in years with a warm wet spring, favorable summer weather with adequate rainfall, and warm sunny fall days with crisp, cool nights.  See the US Department of Agriculture Forest Service website for more information on the Science of Fall Colors.

INVASIVE ALERT

Japanese Honeysuckle (Lonicera japonica) is a rapidly spreading nonnative vine that competes for both above- and below-ground resources, inhibiting the growth of desirable trees, shrubs, grasses, and wildflowers.  A woody perennial vine, Japanese honeysuckle retains its leaves well into winter (year-round in mild climates). Hand pulling young vines is effective only if all roots are removed.  Any roots left in the soil will resprout.  A foliar spray may be a more effective way to kill the entire plant. The best time to spray is autumn and early winter after most native plants have lost their leaves or are dormant, but before a hard freeze (25°F). Foliar sprays are less effective in spring because the herbicide does not thoroughly move from the leaves into the roots during spring growth. For additional information on methods for eradicating Japanese Honeysuckle, refer to the Blue Ridge Partnership for Regional Invasive Species Management (PRISM) fact sheet. Also see the  Invasive Plant Control Calendar in the May 2022 issue of The Garden Shed.

Featured Photo of ‘Purple Dome’ Asters (Symphyotrichum novae-angliae):  Pat Chadwick

 

Compact Versions of Commonly Grown Trees and Shrubs

• October 2, 2022
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Making the most of limited landscaping space can be a challenge. This is particularly true if you live in a townhouse, condo, or urban neighborhood where houses are built on small lots.  Depending on the size of the lot, conventionally sized trees or shrubs may be too large for the space.  Fortunately, compact versions of many commonly grown trees and shrubs may offer a viable solution to the problem.

ABOUT COMPACT WOODY PLANTS

As its name implies, a compact plant (often referred to as a dwarf) is one that, when fully mature, is typically shorter and narrower than the species.  Many compact woody plant varieties have evolved naturally without human intervention.  Many other compact plants have been developed through the efforts of plant breeders and horticulturalists and are referred to as cultivars (short for cultivated variety).  Here’s a tip:  Some compact plants include the word ‘nana’ in the name.  This is from the Latin ‘nanus’ which means dwarf or small.

Using compact woody plants makes sense when you consider they:

• Offer the same blossoms, foliage, and seasonal interest as their full-sized counterparts.
• Provide height, mass, and structure in the landscape but on a smaller scale.
• Are useful in foundation plantings or along narrow walkways or garden paths where full-size specimens might overwhelm the space available.
• Generally require less pruning due to their smaller size.
• May be used in container gardens where a full-size counterpart can’t fit. Many of the smaller dwarf conifers, for example, are useful in year-round container gardens.

While compact woody plants offer many obvious benefits to the homeowner with limited gardening space, they are also useful in larger landscape settings where they may:

• Blend in more effectively than full-size versions in mixed borders.
• Be grouped together in a low-maintenance mass planting, which is an ideal way to cover the soil, control weeds, and cut back on the use of so much mulch in the landscape.
• Work well in a low hedge where a barrier is desired but on a modest scale.

A SAMPLING OF COMPACT TREES AND SHRUBS

The compact woody plants described in the following paragraphs are just a few examples of the many commercially available alternatives to conventional, full-sized plants.  Unless indicated otherwise, these plants are native to the eastern United States, deer resistant, and suitable for growing in the piedmont area of Virginia.  Many of these compact cultivars have been determined to be as equally beneficial ecologically as the straight species. For more on woody plant species native to Virginia, check out the Plant Virginia Natives website as well as The Garden Shed article entitled Coming to a Garden Center Near You in the April 2022 issue.

All sizes listed are approximate.   Actual plant sizes may vary depending on site conditions, climate, and the age of the plant.  Many plant tags list the “mature” size of a plant when it reaches 10 years of age.  However, plants may continue to grow well beyond that point and may exceed the size stated on the tag.  Should that be the case, the plant may need an occasional pruning to contain it within the space available.  Keep this possibility in mind as you visualize how the plant will fit within your landscape.

Fothergilla (F. gardenii), also called dwarf Fothergilla, is a deciduous shrub that suckers but is otherwise trouble free.  It typically grows 3’ tall and wide with white bottlebrush-type flowers in spring, attractive bluish-green disease-free foliage in summer, and brilliantly hued late fall foliage.  Don’t confuse this species with Fothergilla major, which is a much larger species at 6’ to 10’ tall and 5’ to 9’ wide.  Examples of compact cultivars include:

• ‘Mt. Airy’ (F. x intermedia) is a hybrid cross between F. gardenii and F. major. It grows 4’ to 5’ tall and wide with an upright habit and displays intense yellow-orange-red fall color. The Pennsylvania Horticultural Society selected ‘Mt. Airy’ for its Gold Medal plant award program in 2014, based on several factors, including multiple seasons of interest, commercial availability, and appropriateness for the Mid-Atlantic region.
• ‘Blue Mist’ grows 2’ to 3’ tall and wide with a rounded habit and attractive frosty-looking blue-green foliage in summer. The size is better suited to a small landscape than ‘Mt. Airy’, but the fall color is not as spectacular.
• ‘Legend of the Small’ (F. x intermedia) grows 2’ to 2.5’ tall by 2’ to 3’ wide and has all the attributes of the species.

Inkberry (Ilex glabra) – This is an upright, rounded, multi-stemmed evergreen shrub that often shows sparse foliage on the lower stems.  The full size of the species is variable depending on the growing conditions but, in general, it averages 6’ to 10’ tall with a wider spread of 8’ to 12’.  Male and female plants are separate from one another. A male plant is required for female plants to produce berries. The berries are normally black and somewhat inconspicuous. The smaller cultivars listed below have a denser habit than the species and are good substitutes for boxwood in the landscape.

• ‘Compacta’ grows 3’ to 4’ tall and 4’ to 6’ wide with a somewhat oval-rounded shape. This female cultivar produces lots of fruits and has good lower stem leaf retention.
• ‘Shamrock’ is a little larger than ‘Compacta’ at 5’ tall and with a compact, rounded, denser habit. It retains its leaves on the lower stems better than the species, but as the plant ages, it will exhibit some loss of leaves on the lower stems.
• ‘Gem Box’ grows 2’ to 3’ tall and wide and retains its foliage all the way to the ground. It looks good as a container plant, blends in well in a mixed border, or used as a short hedge.
  

  Inkberry (Ilex glabra) ‘Compacta’.  Photo courtesy of Missouri Botanical Garden Plant Finder

Oakleaf Hydrangea (Hydrangea quercifolia) is a deciduous multi-stemmed, mounding shrub that thrives in full sun to part shade in moist soil.  It is noted for its distinctive, boldly textured foliage, showy white flowers, and stunning fall foliage.  At 10 years, it can reach an average of 8’ tall and wide.  Several considerably smaller cultivars are listed below.

• ‘Little Honey’ grows 3’ to 4’ tall and 3’ to 5’ wide and provides a long season of interest. The deeply lobed spring foliage on this dwarf cultivar is golden-yellow maturing to chartreuse in summer and crimson red in autumn.
• ‘Munchkin’ grows 3’ tall and 5’ wide. This cultivar, which was developed by the U.S. National Arboretum, produces many flowers that are held above the foliage.  The white flowers gradually turn a medium pink color as they age.
• ‘Sikes Dwarf’ grows 2’ to 3’ tall and 3’ to 4’ wide. It is more densely leaved and less spreading than the species. The leaves and flower panicles on this dwarf are much smaller than those of the species.
• ‘Pee Wee’ grows 3’ to 5’ tall and 3’ wide. The leaves and flower panicles are about half the size of those of the species. It has a more restrained growth habit and doesn’t sucker as much as the species.
  

  Oakleaf Hydrangea (Hydrangea quercifolia) ‘Munchkin’.  Photo:  Pat Chadwick

Redbud (Cercis canadensis) is a small tree by nature, topping out at of 20’ to 30’ with a spread of 25’ to 35’.   Smaller, dwarf cultivars, including some weeping varieties, of this popular spring-blooming deciduous tree include:

• ‘Ace of Hearts’ grows 12’ tall by 15’ wide and is approximately half the size of the species. It features abundant light violet-pink flowers, a dome-shaped canopy, and small, heart-shaped leaves.  The dark green summer foliage turns bright yellow in fall.
• ‘Rising Sun’ is a completely different looking redbud. The foliage occurs in varying shades of orange, yellow, and gold. It grows 12’ to 15’ tall and about 8’ wide.
• ‘Ruby Falls’ is a weeping form with reddish-purple leaves that grows to an average height of 6’ and 4’ wide.
• ‘Don Egolf’ is a non-native compact redbud worthy of mention. This Chinese redbud (Cercis chinensis) cultivar was introduced by the U.S. National Arboretum, where it grew only 9’ tall and 9.5’ wide at 15 years. It does not develop pods (fruits) like its canadensis cousins.
  

  Redbud (Cercis canadensis) ‘Ace of Hearts’.  Photo:  courtesy of Missouri Botanical Garden Plant Finder

Redcedar (Juniperus virginiana) is considered by many to be a “weed” tree because it can quickly populate vacant properties.  However, it can be very attractive in the right setting.  It grows 40’ to 60’ high on average and up to 20’ wide.  It is dioecious, meaning there are separate male and female plants.  The females produce small bluish berry-like cones.  Two smaller, more compact varieties are:

• ‘Brodie’ grows 20’ to 25’ tall but is comparatively narrow at 4’ to 6’ wide at maturity. This female cultivar has an attractive tight, columnar form that works well as a hedge or screen.
• ‘Taylor’ grows 15’ to 20’ high and 3’ to 4’ wide, is assumed to be male (since it does not produce the berry-like cones), and is believed to be resistant to cedar apple rust (Phomopsis juniper blight). It can be used as a narrow vertical accent or as a screen. The Missouri Botanical Garden selected this cultivar as a Plant of Merit in 2016.
  

  Redcedar (Juniperus virginiana) ‘Taylor’.  Photo:  Missouri Botanical Garden Plant Finder

Red Chokeberry (Aronia arbutifolia) and its smaller but less showy relative Black Chokeberry (Aronia melanocarpa) are deciduous shrubs that are valued in the sunny border for their high wildlife value, showy spring blossoms, colorful berry displays, and glorious red autumn foliage. Sources vary on their deer resistance, but the Rutgers University’s Landscape Plants Rated by Deer Resistance rates A. arbutifolia as “seldom severely damaged.”  While Aronia grows an average of 6’ to 10’ tall and wide, smaller cultivars include:

• ‘Low Scape Mound’, a cultivar of melanocarpa, measures a mere 1’ to 2’ tall and 1.5’ to 2’ wide. Like the full-size species, it displays showy black fruit and red fall foliage.
• ‘Nero’ is a popular melanocarpa cultivar that grows 3’ to 4’ tall but has all the attributes of the species.
• ‘Brilliantissima’, a widely available cultivar of arbutifolia, is slightly smaller than the species at 6’ to 8’ tall and wide but has superior scarlet red fall foliage and more abundant clusters of glossy red fruits. In Michael A. Dirr’s Manual of Woody Landscape Plants, he states: “Having observed this form in greater numbers, I am giving it a first class rating.” This cultivar may be too large for some small landscapes but if space allows, it will earn its keep in the right setting.
  

  Red Chokeberry (Aronia arbutifolia) ‘Brilliantissima’. Photo: Pat Chadwick

Red Twig Dogwood (Cornus sericea) is a deciduous, shrubby form of dogwood with colorful stems that make a huge impact in the winter landscape. The best stem color appears on new growth, which turns bright red (or yellow depending on the cultivar). A sizeable shrub, the species can grow 8’ to 10’ tall with a spread of 10’ or more.  In comparison, a number of compact cultivars are less than half that size, including:

• ‘Arctic Fire’ tops out at 3’ to 5’ tall and wide.
• ‘Kelseyi’ grows 2’ to 2.5’ tall and wide with a rounded shape.
• ‘Pucker Up’ grows 3’ to 4’ tall and wide. The name of this plant is inspired by the small, dark green leaves, which have a very attractive puckered look.
  

  Red Twig Dogwood (Cornus sericea) ‘Arctic Fire’.  Photo: courtesy of Missouri Botanical Garden Plant Finder

River Birch (Betula nigra) is a deciduous tree that grows 40’ to 70’ high and 40’ to 60’ wide. It is “perhaps the most heat resistant of all North American birch species,” according to Dirr’s Hardy Trees and Shrubs.  In his book Bringing Nature Home, author Douglas Tallamy states that birches provide food for a variety of wildlife, including several hundred species of moths and butterflies, songbirds, and small mammals.  Compact varieties include:

• ‘Little King’ (Fox Valley®) is a dense, compact cultivar with a uniform, compact habit. It grows 10’ to 15’ tall and 12’ wide. The cinnamon-brown to pale salmon bark is similar to the species.
• ‘Studetec’ (Tecumseh Compact™) is a compact cultivar with a rounded crown and graceful, drooping branches. It grows 10’ to 15’ tall with a spread of 15’ to 20’. The exfoliating trunk and branches expose cinnamon-colored bark.  Best used in a moist site.  It doesn’t do well in drought conditions.

Southern magnolia (Magnolia grandiflora) can grow 60’ to 80’ tall and 30’ to 50’ wide, which is much too large for a small yard.  Several smaller versions of this evergreen species include:

• ‘Little Gem’ grows 20’ to 25’ tall by 10’ to 15’ wide. It is a widely planted, popular smaller species with leaves and flowers about half the size of those on a standard magnolia.
• ‘Teddy Bear’ grows 15’ to 20’ tall by 12’ wide. It is a little smaller than ‘Little Gem’ but grows faster and has larger flowers.

Sweet Pepperbush or Summersweet (Clethra alnifolia) grows 4’ to 8’ tall and slowly spreads by suckering (sends out new shoots from the roots).  The flowers of this deciduous shrub bloom white in mid- to late summer, but several cultivars bloom in shades of pink.  The flowers are fragrant and attract butterflies and bees. This low-maintenance plant prefers part shade and consistently moist soil.  The glossy deep green foliage is disease-free and very attractive, which makes this a good selection for foundation plantings.  The Virginia Native Plant Society honored this deserving shrub as Wildflower of the year in 2015.  Several small cultivars include:

• ‘Hummingbird’ is a popular, slow-growing selection that grows 2’ to 4’ tall by 3’ to 5’ wide. It produces sweetly fragrant white flowers in midsummer and tends to be more floriferous than the species.
• ‘Sixteen Candles’ is another popular selection that is similar in size to ‘Hummingbird’ but holds its 6” white flowers more upright.
• ‘Sugartina Crystalina’ grows 2’ to 3’ tall and wide with fragrant, creamy-white flowers.

Virginia Sweetspire (Itea Virginica) is a deciduous shrub that grows 6’ to 10’ tall and 4’ to 6’ wide or wider. It is appreciated for its abundant display of white bottlebrush flowers in spring and red and purple fall color.  It grows well in sun or shade. While it prefers moist soil, where it will spread by suckering, it adapts to dry soil once it is established.

• ‘Little Henry’ grows 3’ tall and wide and is a dwarf form of award-winning ‘Henry’s Garnet’, which is considered one of the best selections in terms of habit, floral display, and fall color. The only real difference between the two is size. ‘Henry’s Garnet’ grows to about 5’ to 6’ tall.
• ‘Merlot’ grows 3’ to 4’ feet tall and wide and has wine red fall color on leaves that persist well into winter.
• ‘Scentlandia’ grows 2’ to 3’ tall and wide with larger, more fragrant blossoms than the straight species.  The fall foliage turns bright orange and red.

Winterberry (Ilex verticillata) is a “must have” deciduous shrub for the winter garden – but only if there’s enough room for two of them.  Winterberry is dioicous, meaning that male and female blossoms occur on separate plants.  To produce berries, a female winterberry must have a male pollinator located within about 40’ to 50’.   The spectacular berry display lingers until late winter when the robins return and devour them. For comparison purposes, ‘Winter Red’, a widely planted variety, grows 9’ tall and 8’ wide, whereas the dwarf cultivars listed below grow less than roughly half that size.

• ‘Berry Poppins’ grows 3’ to 4’ tall and 4’ wide. Use ‘Mr. Poppins’ (4’ tall and wide) as the male pollinator.
• ‘Little Goblin’ grows 3’ to 4’ tall and wide. Use ‘Little Goblin Guy’ (4’ tall and wide) as the male pollinator.
• ‘Nana’ Red Sprite’ (also sold as Red Sprite) grows 3’ to 4’ tall and 5’ wide with an attractive mounded habit. Use ‘Jim Dandy’ (3’ tall and wide) as the male pollinator.  In 2015, the Missouri Botanical Garden designated this cultivar as a Plant of Merit and in 2016, the Pennsylvania Horticultural Society selected it for its 2016 Gold Medal award.
  

  Winterberry (Ilex verticillata) ‘Little Goblin’.  Photo:  Pat Chadwick

SUMMARY

Compact woody plants fill a need in small landscapes that can’t accommodate full-size trees and shrubs.  Even in larger landscapes, these smaller selections may aesthetically perform better in certain landscape applications than their full-sized counterparts. The compact trees and shrubs described in this article are just a sampling of the many, many smaller varieties available for smaller landscapes. Because shrubs and trees are major long-term investments, it is wise to research plant choices thoroughly before committing to them to make sure they are right for your landscape needs both now and in the future.

SOURCES:

Dirr’s Hardy Trees and Shrubs, Dirr, Michael A., 1997

Essential Native Trees and Shrubs for the Eastern United States, Dove, Tony and Woolridge, Ginger, 2018

Gardener’s Guide to Compact Plants, Walliser, Jessica, 2019.

Manual of Woody Landscape Plants, Dirr, Michael A., 2009

“Eastern Redcedar,” University of Maryland Cooperative Extension Factsheet

“Fothergilla,” North Carolina State University  Dwarf Fothergilla Factsheet

“Ilex verticillata”  Common Winterberry, University of Connecticut College of Agriculture, Health and Natural Resources

Landscaping with Dwarf Conifers, American Conifer Society,  Conifer Size Categories

“Magnolia,” Clemson Cooperative Extension Factsheet HGIC 1015

Oakleaf Hydrangea (Hydrangea Quercifolia – Smaller Selections), University of Kentucky College of Agriculture, Food and Environment

“Redbud,” Clemson Cooperative Extension Factsheet HGIC 1021

Rutgers University List of Landscape Plants Rated by Deer Resistance

Selecting Landscape Plants:  Conifers, Virginia Cooperative Extension Publication 426-605

“Summersweet Clethra,” Clemson Cooperative Extension Factsheet HGIC 1090

“The Evaluation and Introduction of a Unique Dwarf River Birch,” Chicago Botanic Garden Plant Evaluation Notes

Tried and True Native Plant Selections for the Mid-Atlantic, Master Gardeners of Northern Virginia website.

“Virginia Sweetspire,” Clemson Cooperative Extension Factsheet HGIC 1080

“Winterberry,” Clemson Cooperative Extension Factsheet HGIC 1871

The Edible Garden in October

• October 2, 2022
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October signals the beginning of the end of our outdoor vegetable and fruit growing season. It’s the last chance to plant a few short cycle vegetables, harvest frost sensitive produce before our first frost, document the gardening year, clean up the beds, and prepare beds for winter. Let’s dig into the possibilities.

Planting

If you planted crops for fall harvest in September, you may already be harvesting fast-maturing plants like some lettuces and radishes. According to the VCE Home Garden Vegetable Planting Guide, those of us in Hardiness Zone 7a are still able to plant baby lettuces, radishes, mustard, and spinach during the first part of the October.  With an average first frost date of October 15th-25^th and a warming trend that may push it later, late planters have the possibility of another crop before winter.

Watch the two week forecast and plan to protect any sensitive crops ahead of predicted frosts to maximize your harvest.

Frost preparation:

To get a better understanding of frost damage and which vegetables are or aren’t susceptible to it, refer to the article Identifying and Preventing Freeze Damage in Vegetables from the Michigan State University Extension.

If you want to nurse plants further into the fall, there are a couple of options:

• Wet your soil: there is some evidence that watering ahead of a frost will keep the air temperature just above the soil up to 5 degrees warmer than dry soil and will maintain the differential overnight.

• Cover your plants: For better protection, cover the crops that aren’t cold hardy. Spun polyester row cover fabric is a proven choice, although gardeners use everything from newspapers to buckets to commercially available water-jacketed individual plant covers. Fabric cover protection varies from 2 to 6 degrees Fahrenheit depending on soil conditions and fabric used. Air space between cover and plants increases the protection over that obtained by simply laying the cover directly on the vegetation. Spun fabric covers let light and water through and can be left in place. Most other options need to be removed during the day after the temperature is above freezing. For more information on row covers please check out the Garden Shed article: Row Covers: A Season Extender with Benefits.

• Cold Frames: Cold frames provide a more permanent way to combat both spring and fall frosts. Tips on construction and on using cold frames are available in the Colorado State Extension article Extending the Season with Cold Frames.

• After frost, cut back asparagus foliage to within 2 inches of the ground.
• If you haven’t done a soil test in a few years, fall is a good time to get one. Organic amendments added in the fall will be ready for plant uptake in the spring. In the Charlottesville/Albemarle area, test kits and instructions are available at the Stagecoach Road entrance to the County Building off the 5^th St Extension.
• There is still time to plant a cover crop. Cover crops protect the soil over the winter, store unused nutrients to prevent them from leeching, and provide organic matter in the spring when tilled under or composted. It is late for planting a mixed crop but Winter Rye is a possible late season solution that adds organic matter and helps break up compacted soil. The article Cover Crops from the University of Maryland Extension provides guidance.

• If you aren’t planting a cover crop, protect the garden soil with a few inches of mulched leaves, aged wood chips, or straw. Mulch reduces nutrient leaching and carbon loss and moderates temperature variation while adding organic matter.
• If you haven’t kept up with garden documentation this year, this is your last chance. It’s a good idea to diagram the garden along with specific crop locations. Crop rotation is an important organic tool for minimizing passing insect and disease problems from one season to the next.
• Vegetable crops in the same botanical family are often susceptible to the same diseases and insects. For crop rotation to be effective, gardeners should not plant vegetables belonging to the same family in the same location for at least three years. Crop rotation in a small garden may be difficult. However, we should rotate our vegetable crops as best we can. You can find an informative listing of plant families in the Penn State Extension article Plant Rotation in the Garden Based on Plant Families.
• Guidance for Fruit Growers 
  • Protect strawberry plants over winter by weeding beds and mulching before temperatures get down to 20° F. Chopped leaves and straw are good mulches. More details are offered in the Iowa State Extension article https://www.extension.iastate.edu/news/yard-and-garden-prepare-strawberry-plants-winter
  • If you are thinking about planting a fruit tree, fall is a good time to do it. Water newly-planted trees thoroughly. Add a 3-inch layer of organic mulch, leaving a 3-4” gap around the tree base, to retain soil moisture and moderate soil temperature. Research has shown that roots will continue to grow until the soil freezes, which is typically late November in Virginia. Stake and wire newly-planted trees only if necessary. Use a piece of rubber hose around the guy wires to protect the trunk. The guy wires should be tied loosely enough so that the tree is able to move a little in the wind. The supports and stakes should be removed once the tree becomes established, usually in a couple of months.
  • Pick up dropped fruit from under fruit trees so that deer and rodents will not be attracted to the fruit or your growing tree. Raking and disposing of diseased leaves will help keep insects and diseases under control next season.
  • High grass and mulch are a haven for rodents whose gnawing can severely damage trunks. Keep the grass mowed around new trees. Be sure that mulch is pulled back 3-4 inches away from the base of the tree.
  • For more information about selection and care (especially the timing and techniques for pruning) for a variety of small fruits, refer to the VCE publication Small Fruit in the Home Garden.

  Ok, got everything taken care of? Relax. You’ve earned it. Hoping for a more leisurely visit with you next month at The Garden Shed.

  Sources:

  Phillips, Ben and Collin Thompson, “Freeze Damage in Fall Vegetables: Identifying and Preventing,” http://msue.anr.msu.edu/news/freeze_damage_in_fall_vegetables_identifying_and_preventing

  October Tips: Fruit and Nuts, VA Cooperative Extension: https://albemarle.ext.vt.edu/content/dam/albemarle_ext_vt_edu/files/hort-tip-sheets/10-14-fruit-nuts.pdf

  Garlic Production for the Gardener, UGA Extension,    https://extension.uga.edu/publications/detail.html?number=C854&title=Garlic%20Production%20for%20the%20Gardener

  Harvesting and Preserving Herbs for the Home Gardener, NC State Extension: https://content.ces.ncsu.edu/harvesting-and-preserving-herbs-for-the-home-gardener