Cover Crops & Mulching
Soil Health & Structure
Healthy soil is at the heart of any garden and building and maintaining soil vitality cannot be overemphasized. Healthy soil consists of an interdependent system of water, minerals, air, decaying plant material hosting a thriving community of microscopic organisms, bacteria, fungi, insects, and worms. Properly putting your garden to bed for winter not only supports but helps this ecosystem to flourish.
Cincinnati soils are "heavy" - high clay content - and this can impede successful vegetable production. Building healthy soil warrants your time and consideration to provide for the necessary improvements. In nature, soil exists as a dynamic regenerating system of water, air, minerals, decaying plant and animal parts, microscopic organisms, insects and worms, bacteria, fungi and rodents. Think of soil as a living being.
Some recommendations for putting your garden to bed
First, weed your garden completely, pull all remaining plant material and move it to the compost pile. Putting the effort into thoroughly weeding the garden in the fall will save you from many, many more hours of weeding in the spring.
Next, shallow turn, clumping, the soil then covering the garden bed with compost and/or organic matter - fall leaves and straw are good for this. Fall leaves that are partially decomposed or shredded work best. An easy way to shred fall leaves is to mow over them with a bagging lawnmower. Then empty the lawnmower’s bag into a container or yard waste bag to transfer to your garden.
Over the winter the compost and/or organic matter further decomposes, in addition, the repetition of the soil freezing, and thawing helps to further break down the material and work it down into the soil. Yes, Mother Nature is our best helper. This process helps integrate the organic matter into our heavy clay soils increasing the soil’s water and nutrient-holding capacity in addition to increasing air pore space. These components contribute to a balanced soil that:
Holds water
Contains nutrients to enliven plant life
Drains well
Recycles plant material and animals in a cycle of life and deat
Compost
Overwinter with Compost
Clump soil, then cover with compost or organic matter i.e., leaves. Compost and/or organic matter further decomposes helping to breakdown heavy clay soils into a healthy garden soil with a water and nutrient-holding capacity in addition to increasing air pore space. Helps replace essential nutrients that have been taken up by past garden crops.
Adding mature compost to your garden soil is important:
It is a source of nitrogen an important nutrient for growing healthy crops.
To provide garden soil a wide variety of beneficial microorganisms, bacteria, fungi, insects, and worms that are necessary for plants to thrive.
Soils with High Bulk Density (a lot of solid matter, including clay, with little pore space) lead to compaction - a difficult environment for plants to grow. A healthy soil structure consists of a combination of solid matter (mineral and organic) and open-pore space (spaces where air and water infiltrate the soil). Compost is a soil conditioner it adds humus to garden soil, which increases pore space for plants roots to grow, the storage of water and nutrients as well as creates a healthy environment for microorganisms, bacteria, fungi in addition to beneficial insects and worms.
Tilling
Use Minimum Tillage. Tilling can be an important part of garden management however it should be done in a thoughtful way and only when needed. Deep tilling disturbs biological layering that occurs in nature. By avoiding, or minimizing this, you allow the action of small organisms living in the soil to do the work for you. In addition, tilling can also turn up weed seeds and encourage their germination. Another problem with repeated deep tilling in southwest Ohio soils is that you can create a “hard pan” layer of compacted soil under the soil surface – the tiller tines over time will create a "hard pan" a compacted layer that makes it impermeable – water, air, and nutrients cannot move beyond this layer and soil can become supersaturated. A tiller is an important tool, with larger home and community gardens where garden beds are 200 square feet or larger. If you are working with a raised wood frame garden bed that is 4x8 to 4x12 feet turning your soil with a shovel and/or spading fork is recommended.
Cover Crops & Green Manures
Green Manure: A crop that is grown and then incorporated into the soil to increase soil fertility and organic matter content.
Cover Crop: A crop grown to protect and enrich the soil, or to control weeds.
- Rodale's All-New Encyclopedia of Organic Gardening: The Indispensable Resource for Every Gardener
Maintain year-round ground cover:
§ Living ground cover reduces topsoil erosion
§ Ground covers add or replace nutrients to soil (i.e., any legume clover or vetch)
§ Ground covers will suppress weed germination
§ Weed control takes forethought and attention to timing. By planting cover crops between rows of food crops, you can add organic matter to soil, reduce soil erosion and increase diversity of available nutrients, in addition to crowding out weeds that can add to your labor time in the garden
Why Green Manure & Cover Cropping…
Improved soil structure, which follows from green manure/cover cropping, allows better penetration as well as retention of moisture. The greater permeability of the soil does not mean that nutrients are lost through leaching. The growing crop absorbs the nutrients from the soil and holds them in its tissue. Many green manure crops are deep rooted enough to reach well into the subsoil, effectively opening the subsoil if it is heavy (which is often the case in an urban setting), creating a deep, loose soil for improved plant growth.
Turning in Cover Crops & Green Manures
To get the maximum benefit out of Cover & Green Manure Crops (except for grasses and cereal grains like Winter Rye) they should be allowed to grow until 90% of the crop has flowered. You do not want to allow the crop to go to seed and re-sow, but allowing the plants to flower will keep them from growing back after turning them in.
"Cocktail" Garden Cover Crop Mixes
Garden Cover Crop Mixes contain combinations of grasses, buckwheat, peas, clovers, and cereal grains providing high biodiversity for soil improvement. The tender cover crop mixes that dieback over winter are particularly useful for the home and community garden bed - because they winterkill turning them into the soil is much easier and can be done earlier in the spring. Walnut Creek Seed is an excellent source for seed and information on Garden Cover Crop Mixes: www.walnutcreekseeds.com
Buckwheat
SEEDING RATE: 1 ½ Lbs. /1000 sq. ft.
SOW: Late spring and summer
TURN UNDER: Summer to early Fall
Good summer cover crop.
Hairy Vetch
LEGUME
SEEDING RATE: 1 ½ Lbs. /1000 sq. ft.
WHEN TO SOW: Spring/Fall
WHEN TO TURN UNDER: Fall/Spring
Vetch is a very effective overwinter crop. In early spring it can be cut back at ground level, leaving stubble that tomatoes, pepper and eggplants can be planted directly into... The green plant mass that is cut can be laid aside allowed to dry then used as mulch around tomatoes, pepper and eggplants. Vetch can also be turned into the soil as with other green manure and cover crops.
Summer Cover Crop Mix – Walnut Creek Seeds
SEEDING RATE: 1 Lbs. /200 - 300 sq. ft.
SOW: Summer, temperatures over 65 F.
TURN UNDER: Late Summer - Fall
The WCS Garden Summer Mix is a complex cover crop mix designed to protect and rejuvenate fallow ground through the summer for planting of late cool season vegetables or fall cover crop. This mix will prevent erosion, provide organic matter for macro and microorganisms, fix nitrogen and provide for some pollinators. All components are untreated and non-GMO for organic gardeners. Cow Pea, Flax, Oats, Oilseed Radish, Pearl Millet, Sunflower, and Sunn Hemp.
Winter Cover Crop Mix – Walnut Creek Seeds
SEEDING RATE: 1 Lbs. /200 - 300 sq. ft.
SOW: Fall, temperatures over 65 F.
TURN UNDER: Spring or matt of dead plant material can be planted directly into
The WCS Garden Fall Cover Mix is a complex cover crop mix designed to winter kill, leaving a surface mulch in the spring requiring little to no management prior to planting. Ideal for cool season vegetable spaces. This combination will loosen topsoil, protect your soil from winter erosion and nutrient loss, suppress weeds. The surface residue will provide food for soil micro and microorganisms which are crucial for healthy soil. This mix will winter kill in a typical Zone 5 Winter. Cow Pea, Ethiopian Cabbage, Mung Bean, Oats, Oilseed Radish, and Pearl Millet.
Raised Bed Mix – Walnut Creek Seeds
SEEDING RATE: 1 Lbs. /200 - 300 sq. ft.
SOW: Fall, temperatures over 65 F.
TURN UNDER: Spring or matt of dead plant material can be planted directly into
The WCS Garden Raised Bed Mix is a complex cover crop mix designed to provide diverse root structures and organic matter to fortify and amend depleted soils. This mix may be used in all garden types and provides pollinators and beneficial insects with fall and spring blooms. This mix will winter kill in a typical Zone 5 Winter. Buckwheat, Austrian winter Pea, Flax, Oats, Oilseed Radish, and Yellow Mustard.
Winter Rye
SEEDING RATE: 2 Lbs. /1000 sq. ft.
SOW: Fall
TURN UNDER: Spring
Please note: Winter rye is an annual cereal grain. The use of winter rye in a home-raised bed can be difficult to turn in, it may require turning a second time, and two to three weeks for it to die back before you can plant in the spring. For the home and community gardeners winter rye is best used as an overwinter green manure crop to prepare the soil in advance of installing a new garden. Germinates in temperatures between 34- and 75-degrees Fahrenheit.
Should you have additional questions please feel free to contact us:
Peter Huttinger
Turner Farm Community Garden Program, Director
peter@turnerfarm.org
513-328-0100
Seed Sources
The below list is of a few local resources for vegetable seed and cover crop/green manure seed.
With each local business the seed available is listed, however contact them first to confirm availability.
Local
Growing Trade Store Pet & Plant
3840 Spring Grove Ave.
Cincinnati, OH 45223
513-541-1321
www.growingtradestore.com
- Vegetable seeds
- Walnut Creek Fall Cocktail Mix (cover crop)
- Hairy Vetch (cover crop)
A. J. Rahn Greenhouses
4944 Gray Rd
Cincinnati, OH 45232
513-541-0672
greenhouses.ajrahn.com
- Cover crop seed in small quantities
Mail Order
Gardens Alive
www.gardensalive.com
- Vegetable seeds
- Cover crops
High Mowing Seed
www.highmowingseeds.com
- Cover crops
Walnut Creek Seed
www.walnutcreekseeds.com
Specialist in cover crop seed
- Cover crops