Memphis’s Annual Garden Plan instructed school gardeners to plant snow peas and fava beans as a cover crop over the winter. They may have grown big, they may have grown small, but here’s how to manage them as you’re planning your spring garden.
Why does Big Green recommend that we plant something that is not edible?
Cover crops are a useful tool that gardeners and farmers use when they or their garden need a break from producing edible crops. Edible crops take up a lot of the available nutrients in a garden, especially nitrogen, phosphorus, and potassium – you may have even taught students about the benefits of NPK! On the other hand, when a garden lays fallow (completely unplanted), it is susceptible to pests, diseases, drying out, and nutrient seepage (heavy rains or winds washing away nutrients in the soil).
Instead, we plant cover crops and/or use soil amendments (provided once a year by Big Green). Cover crops protect the soil from the dangers listed above and also provide even more nutrients and organic matter to the soil. Even if you think you have very little time for the garden over the summer or winter breaks, you can broadcast (scatter) these cover crop seeds and they will sprout and take care of themselves for the most part. If you are able to stop by and water a a few times over the summer, thought, it never hurts!
How do we get the benefits of the cover crops?
Some cover crops ARE edible (snow peas, fava beans, cowpeas) and can be distributed to students or teachers. Other cover crops are planted primarily for their benefit to the soil. Here are the steps to take when you are cleaning out cover crops:
1. Use scissors, your hands, or a scythe to cut the tops off of all the plants, leaving their roots in the soil. Compost or throw away this top part of the plant. You can also leave these parts in the soil if you don’t mind a messier looking garden bed. They will break down! This is a simpler way to compost small amounts of green matter without setting up a compost area.
2. When only the roots are remaining, take a shovel or a hand trowel and turn over the soil with the roots in it. This mixes the roots with the soil and also prevents them from growing another stem and leaves.
3. After the soil is turned, leave the garden undisturbed for 2-3 weeks before planting your new garden! Most of the roots, stems, and leaves will have broken down; if not, plant as usual and resist the urge to remove all of the old plant parts.
4. Pro tip: if you want the cover crop to break down more quickly, or you are short on time, cover the beds with black plastic (tarps or opened trash bags) and weigh them down with a brick or something heavy. The black plastic will accelerate decomposition underneath!
TLDR (too long, didn’t read): If you planted fava beans, snow peas, or another cover crop, pull up and break apart the plants and mix them in with the soil 2-3 weeks before you plant your spring garden for healthy and happy future fruits and veggies!