What is cover cropping? Cover cropping is a time-tested method of planting crops between vegetable rotations to restore nutrients and structure to your soil. Detailed benefits include protecting soil from runoff, reducing surface crusting, adding organic material, and suppressing weeds, diseases, and pests.
After spring and summer’s growing and harvesting seasons, your soil will need an extra boost of nutrients. Summer may be the perfect time to improve fields and boost fertility with a cover crop.
According to the College of Agriculture at Cornell University, ideal summer cover crops for June and July are sudangrass and buckwheat. An advantage of buckwheat is it is native to the southern California region and works in less than a month. In contrast, sudangrass requires two months but is one of the best cover crops for providing soil with active carbon thanks to its extensive root system.
- Shovel or trowel (or rototiller for very large areas)
- Cover crop seeds of your choice- usually legumes, grasses or mixed blends
1. Pull out the remains of old crops in the bed and compost.Rake the area smooth.
2. Broadcast the cover crop seeds. This means scattering them broadly and evenly over the surface of the soil, tossing them in handfuls, at the rate according to the seed package. You can be generous.
3. Rake over gently to cover them.
4. Spread a layer of straw so birds don’t eat the seeds.
5. Water every day until plants are at least a few inches tall. Water is as important for cover crops as it is for vegetables.
When to Till Under
When your cover crops are fully mature (but before they flower and seed), you will want to “turn under” or “till” them into your soil. You have two options for this:
- You can dig the whole plant into your soil to decompose, which will give your beds extra nourishment if you have time. You will want to wait until most of the stems and leaves have decayed before planting the garden.
- If you want to use the bed sooner, you can mow the stems and leaves, put them in your compost pile, and till under just the lower stems and roots.
How to Till
- Dig the cover crop by hand with a shovel or spade (small areas) or with a tiller (large areas).
- Till legumes before they flower. Grasses can go under anytime while they are alive and healthy.
Some farmers let cover crops flower before tilling the plants under because the flowers attract beneficial insects. Legumes, however, are always turned into the soil before the plants mature (before they make flowers or seeds) in order to take advantage of the nitrogen release from the roots as the plant dies.
If legumes are allowed to reach the flower stage and set seed, most of the nitrogen is used up.