When you have harvested your last at the end of the growing season, you may be ready to take a break from growing (at least outdoors). But your garden soil will need rejuvenating. Growing crops uses up the soil’s nutrients and nitrogen. If you want your garden to be ready and fit again for planting next spring, do plan to sow cover crops in late fall for the winter.
Sowing Cover Crops
All cover crops or green manure are sown the same way:
- Prepare the soil. If your soil needs amendments, add them. Spread the necessary amendments on the bed then turn them all in to about 10-12 inches deep.
- Smoothen the surface. Rake the surface smooth and pull a layer of soil off the edge of the garden bed. The soil you set aside will be used to cover the seeds for germination. Most green manure seeds need a thin layer – about ¼ inch – of soil spread on top of them in order to germinate.
- Broadcast the seeds. Scatter the seeds by hand over the soil. Spread seeds thinly and broadcast twice for better results. When you broadcast a second time, it should pass at a right angle to the first.
- Cover the seeds. Rake the seeds into the top ¼ inch of soil lightly then spread the soil you set aside over the seeds to cover them. Tamp down the soil gently using a square of plywood or brick or anything with a flat face. Water lightly but thoroughly and make sure the seeds are wet. This will give them a good start to germination.
Tilling Cover Crops
Wait as long as you can before tilling in your green manure. This will ensure your soil will get the most amount of organic matter from your cover crops.
Let the cover crop grow until about 2 weeks before you want to start to plant in your garden. Or else, wait until the cover crop is about to flower before you till them under. Some green manure like winter rye harden or become more fibrous and woody as they start to flower making it difficult for them to break down after they are tilled in. For best results, till in before the crops flower so they will decompose quickly.
If you are not yet ready to till but the cover crop has already started to flower, just cut the top growth down and either leave the cuttings in the bed or compost them. There will be regrowth from the rootstock, just let that growth until you are ready to till.
Never wait until the green manure has begun to go to seed because by then, the plants will have become too fibrous and very hard to break down. If the crop has gone to seed, cut the top growth down and compost it and then till the rootstock in.
Learn more about gardening organically in our Fresh Organic Gardening Guide.