These Are the Best Edible Cover Crops to Plant This Summer

Sunflowers provide food for birds, are great for the soil, and are bright and cheerful. (Jamil Raza/Shutterstock)

Healthy soil is critical to a robust, productive garden, and as such should never be left fully exposed to detrimental sun, wind, and rain. At the very least, an organic mulch should be added to dormant areas—even the whole garden if it’s left fallow.

However, this is a wasted opportunity. Wouldn’t it be even better to plant some easy-care, heat-loving, soil-saving edibles to get a jump on and enhance the fall harvest?

Bodacious Benefits

The idea behind a cover crop is to provide food and habitat for soil organisms, keep the soil cooler in high heat, reduce evaporation and summer watering demands, and protect soil from eroding its valuable organic matter and nutrients. All of which are of great benefit to the remaining plants in the garden.

Sometimes referred to as “green manure,” cover crops will also reduce the need for herbicides by helping prevent weed seeds from sprouting and ideally are a rich fertilizer for the next crop. This is particularly true of the nitrogen fixers, such as black-eyed peas, which can be grown from an inexpensive bulk bag of grocery store dried peas.

Grab a bag or choose from the list below, remembering that the best approach is to keep things simple with one or two crops to start.

‘Til The Cows Come Home

Several types of legumes are popular cover crops because of their resilience and longevity; they typically last until the first frost or even longer in warmer climates.

Cowpeas offer rapid growth and drought tolerance because they have a deep taproot, and they are renowned nitrogen fixers. (Photo Win1/Shutterstock)

Cowpeas in particular offer rapid growth and drought tolerance because they have a deep taproot, and they are renowned nitrogen fixers. Their flowers lure pollinators and other beneficial insects, and they provide good weed suppression.

The most popular is the black-eyed pea (also known as field pea or southern pea). It was even grown in Thomas Jefferson’s garden. Other choices include Pinkeye Purple Hull, Red Ripper, Ozark Razorback, Carolina Crowder, Peking Black, Rouge et Noir (red and black), and Tohono O’odham (Papago) to name a few.

Soybeans (aka forage soybeans) can also be grown from a grocery store bag. They offer the benefits of cowpeas but are less tolerant of drought and poor soil. On the upside, they are more tolerant of cool weather and “wet feet” (roots).

Spring peas grow fast, but offer lower nitrogen return than the others. They work well in situations that require a large, vining growth habit.

Sweet Solution

Sweet potato leaves make a great salad. (Deborah Lee Rossiter/Shutterstock)

Although not normally thought of as a cover crop, sweet potato does surprisingly well. They’re not actually in the potato family but from the morning glory genus. As a root crop, they are extremely heat tolerant with sprawling vines featuring large, heart-shaped leaves that help retain moisture, cool the soil, prevent erosion, and prevent weed seeds from sprouting. Best of all, the leaves are edible and make a tasty salad.

Beauregard is the most common and can be grown from organic supermarket potatoes. Others, such as Carogold, are designed to be particularly disease resistant, and there are purple varieties, such as Okinawan as well. They need a relatively long growing season of three to six months before frost and don’t like the overly wet soil, which can lead to potato rot.

Soil Bucking Up

Nutrient-rich, gluten-free, heart-healthy, and blood pressure-reducing buckwheat can bloom in as little as 30 days, with flowers that attract pollinators and other beneficial insects. It offers excellent weed smothering when planted densely together. It is also allelopathic, meaning that it releases a chemical to further suppress some weed seeds.

The fine roots offer good topsoil conditioning and are known to “unlock” phosphorus in soil while capturing some nitrogen and potassium that might otherwise be lost to runoff. Best of all, it doesn’t require tilling in—just chop and drop it for one of the best green manures.

Smiling Faces

When it comes to soil rejuvenation, few plants work as well as the sunflower. Their deep taproots break up even the most compacted soil to bring up water, microbes, and nutrients from deep in the soil at levels most other cover crops can’t reach. They’re also highly allelopathic, releasing a chemical that suppresses a long list of other weeds and other plants.

While the black oilseed variety is grown most commonly as a cover crop on a commercial level and backyard birds find its thinner shell easier to open, the black and white striped shell varieties are considered best for eating. Opt for the taller plants with huge faces to get the biggest seeds and more of them.

Adding a cover crop to the rotation will significantly improve soil health.

Soil Boosters

Grasses and millets are excellent for adding biomass—plant-stored chemical energy produced by photosynthesis—to soils.

Marvelous Millets

Pearl millet thrives in hot conditions and can be planted with cowpeas or soybeans for a more diverse summer solution. On the other hand, Japanese millet is the answer when a weed-smothering crop is needed for flooded soils and areas of standing water.

Generous Grasses

Sudangrass is a fast-growing soil improver and excellent weed suppressor. It can also be planted as a solo crop or with cowpeas and sunflowers. The hybrid sorghum-sudangrass (also known as Sudex, Sudax) is similar, growing to a robust six to 12 feet tall.

Tough Teff

A staple grain in Ethiopia, teff is extremely tolerant of heat and drought. In fact, it needs heat to grow up to its full weed-suppressing potential. Its fine root structure leaves soil clump-free for the next crop.