How to plant a cover crop in your vegetable garden

My garden had limited success this year for a lot of reasons — my cat harassed my seedlings, extremely hot days during spring wilted some of my transplants, flea beetles ravaged my eggplants, my squash plants smothered my melons, my tomatoes and peppers weren’t pollinated as well as I’d hoped and nothing grew very big on the east side of the garden.

Despite all the issues, I still enjoyed plenty of squash, zucchini, cucumbers, beets, radishes and lettuce. And I’m hoping to get some corn, broccoli, tomatoes and peppers before the end of summer.

There are definitely some things I will do differently next year, but to ensure next year’s success I’m going to get started this year. 

Cover crops can smother weeds, loosen compacted soils, capture excess nutrients, prevent erosion and some can even add nitrogen to the soil. Planting cover crops during late summer and early fall is a great way to improve your garden soil through the winter.

What are cover crops?

Cover crops are grains, grasses, brassicas and legumes that grow during fall and winter that can be cut and plowed or tilled under in the spring. During active growth, their roots penetrate and loosen compacted soils to allow better air and water penetration while holding surface soil in place and preventing erosion. They help reduce weed growth in fallow gardens. Additionally, legume cover crops add nitrogen to the soil.

Planting cover crops

You can plant your cover crop all at once after you clear the debris out of your garden or you may choose to sew it in sections as your fruit and vegetable crops reach the end of their growing seasons. Either way, seeding your cover crop earlier in the growing season is ideal for good establishment.

Planting a cover crop is simple.

1. Clear out debris from fruit and vegetable plants.
2. Rake garden smooth, removing leftover debris and stones.
3. Spread seed according to recommended rates (below).
4. Lightly rake after seeding.
5. Water cover crop with hose set to a fine mist.
6. Add a complete fertilizer (10-10-10) at 10 pounds per 1,000 square feet. Use a lower nitrogen fertilizer (5-10-10) if you plant legumes.

Recommended planting rates

Annual Ryegrass – Plant August through October at a rate of 1 to 2 pounds per 1000 square feet. 

Oats – Plant until September at a rate of 4 pounds per 1000 square feet.

Wheat – Plant until October at a rate of 4 pounds per 1000 square feet.

Winter Rye  – Plant until November at a rate of 4 pounds per 1000 square feet. 

Brassicas – Plant tillage radishes, turnips and rapeseed in August at a rate of 1 pound per 1000 square feet. 

Alfalfas and Clovers – Plant in August or September at a rate of 1 to 2 pounds per 1000 square feet. 

Cover crop seeds can be purchased at a local garden center, farm store or online using their application rate chart.

Tilling cover crops into the soil

Cover crops can also be turned under to add organic matter to the soil in the spring, which helps support beneficial bacteria, fungi, earthworms and other life forms that improve soil structure and fertility.

As soon as the ground is dry enough, cover crops should be turned under, allowing at least 2-3 weeks before spring planting to decompose. 

Do not allow your cover crops to go to seed before tilling them into the soil or they may become unwelcome weeds. Plants should be cut down just before they flower.

Resources

• Penn State Extension