Green Manure Magic

Last blog I covered covering open planting beds with shredded leaves to protect the soil, sort of like building a cozy winter's cape.  That's a lot of c's in one sentence.  So allow me to switch gears but continue the conversation about your garden soil and other considerations for winter care.
 

Close Up Cover Crop - Austrian Peas/Winter Rye

Another "covering" option for bare soil is to plant a green manure, also known as a cover crop.  From early Romans to the first American settlers, farmers have been using green manures to replenish, improve and prevent soil erosion.  Fields, or in our yards - planting beds that grow crops in the same location year after year need a break or an alternate crop that will enhance the soil by replacing lost nutrients. Planting green manures also improves soil quality (tilth), the soil's water holding abilities and provides a nice environment for beneficial earthworms and soil microorganisms to thrive.

Green manures can be direct seeded in the fall, spring or summer, just be sure to give the cover crop enough time to decompose before planting the next season of vegetables or annuals. Allow at least six weeks or longer to completely break down. If planted in the fall the hardy crops like winter rye and field peas will grow through the winter. Buckwheat and clover winter kill.  

Be careful not to let the crop go to seed, this is more of a consideration with spring or summer planted green manures. 

Rake area, spread seeds, cover seeds with soil and water

The planting procedure is simple - use several seeds, enough to fully cover the bare surface to prevent soil from blowing away.  In addition, this blanket of green will keep weeds out through the winter and when turned over in late winter and allowed to break down, the soil will be super charged with organic nutrients.  Use legume-type seeds for a beneficial nitrogen fix. Check the handy guide below for seed options based on the planting season.  Chart from the University of Wisconsin Horticulture, compiled from Johnny's Selected Seed Company and Cornell University Department of Horticulture.   

Check with your local garden center for seed availability or mail order.  

This bed was planted in October with winter rye and field peas. It's okay to mix seeds.

This bed was turned over in late winter and allowed several weeks to break down before planting.

Cover Crop	Sowing Time	Seeding Rate Per 100 sq. ft. (10’ x 10’ Garden)	Does This Plant Fix Nitrogen?	Growth Rate	Primary  Uses/ Comments
Buckwheat	Spring, Summer	2 lb	No	Fast	Is easily worked into the soil. Attracts pollinators and beneficial insects. Re-seeds prolifically.  DO NOT allow to go to seed.
Clover (Sweet)	Spring, Summer	½ lb	Yes	Medium	Grows better in high pH soils than other clovers.
Oats	Late Summer, Early Fall	4 lb	No	Medium	Likes well drained soils. Dies over the winter. Makes a good choice in areas to be worked early the following spring.
Peas (Field)	Spring, Early Fall	5 lb	Yes	Fast	Can outcompete many weeds.
Radish (Oilseed)	Fall	1 lb	No	Fast	Is easily worked into the soil.
Rye (Winter)	Fall	4 lb	No	Fast	Easy to grow. Grows fast. Can be planted late in the season.
Ryegrass (Annual)	Late Summer, Early Fall	1 lb	No	Fast	Easy to grow.
Wheat (Winter)	Late Summer,  Fall	2 lb	No	Fast	Needs fertile soil. Does not like low pH soils.

                                                                Chart from Wisconsin Horticulture

Summer planted buckwheat, beautiful plant and attracts beneficial insects!