Home & Garden Garden 10 Best Examples of Cover Crops for Your Small Farm By Lauren Arcuri Writer Swarthmore College Lauren Arcuri is a freelance writer and an experienced small farmer based in rural Vermont. our editorial process Lauren Arcuri Updated March 05, 2021 Fact checked by Betsy Petrick Fact Checker Ohio Wesleyan University Brandeis University Northeastern University Betsy Petrick is an experienced researcher, writer, and producer. Our Fact-Checking Process Article fact-checked on Dec 22, 2020 Betsy Petrick Treehugger / Hilary Allison Share Twitter Pinterest Email Garden Urban Farms Planting Guides Indoor Gardening Insects Cover crops are plants that are grown to suppress weeds, help build and improve soil, and control diseases and pests. They're sometimes called "green manure" or "living mulch," since they can add nitrogen to your soil and boost fertility without using chemical fertilizer. Choosing the right cover crop depends on the planting season and your local climate. From flowering clovers to winter grasses, and even food crops like okra, there are cover crops for every season and a variety of purposes. Here are 10 of the best cover crops that small-scale farmers can grow to improve soil quality. Some of the plants on this list are toxic to pets. For more information about the safety of specific plants, consult the ASPCA's searchable database. Winter Rye (Secale cereale) Tier Und Naturfotografie J und C Sohns / Photographer's Choice RF / Getty Images Winter rye is a great annual late-season cover crop to plant in the fall or early winter. It can even be planted after the first light frost and still grow tall enough to be a viable cover crop. With its deep root system, its highly drought resistant and excels at loosening compacted soil. It's often planted in tandem with a legume like clover, which gives a structure for these climbing plants to ascend and provides the next season's crop with nitrogen in the soil. USDA Growing Zones: 3-10 Sun Exposure: Full sun or partial shade Soil Needs: Prefers well-drained, loamy soil; tolerates both dry, sandy soil and heavy clay Common Buckwheat (Fagopyrum esculentum) imagenavi / Getty Images Common buckwheat is an excellent choice for a fast-growing summer season ground cover. This annual grain can prevent erosion, outcompete weeds and attract pollinators with its abundant blossoms. Because it can mature in as little as 40 days, it's an ideal crop in fields and garden beds that would otherwise go unused in between spring and fall cool-weather crops. It also has a large, fine root system that can access phosphorus in the soil efficiently, leaving it on hand for the next crop. It's important to cut or mow buckwheat before it goes to seed, as it can become a weed in the next planting otherwise. USDA Growing Zones: 4-11 Sun Exposure: Full sun Soil Needs: Prefers well-drained soil; can tolerate acidic, alkaline, heavy, and light soil Crimson Clover (Trifolium incarnatum) KOKI TAKADA / Getty Images Crimson clover is a widely used annual cover crop that is useful for its role as a nitrogen fixer that adds fertility to your soil. For winter use, it should be planted six to eight weeks before the first expected frost. It can survive winters in warmer climates, but will generally die off over winter in zone five or lower. It can also be planted in spring, as soon as frost danger has passed, to prepare soil for summer crops. Thanks to its shade tolerance, it can be used in orchards to prevent erosion. USDA Growing Zones: 4-10 Sun Exposure: Full sun or partial shade Soil Needs: Prefers well-drained sandy loam; grows in most soil types except very acidic or alkaline soils Sorghum-Sudangrass (Sorghum × drummondii) dszc / Getty Images Sorghum-Sudangrass is a hybrid annual cover crop that grows quickly, prefers the heat of summer and forms an extensive root structure. Due to its fast growth rate, it's a great weed suppressor. It can be mowed down several times over to course of the summer, which prevents it from going to seed and increases the root system even further. It's an especially effective crop when it comes to revitalizing compacted and overfarmed fields. USDA Growing Zones: 4-10 Sun Exposure: Full sun or partial shade Soil Needs: Prefers well-drained, fertile soil; tolerates most soil Hairy Vetch (Vicia cracca) Grigorii_Pisotckii / Getty Images Hairy vetch is an annual legume known for it's winter hardiness and commonly grown in northern climates. It's well-suited to use as a winter companion plant for tomatoes, which can be planted in the mulch of the cut hairy vetch in spring. It's a powerful nitrogen fixer, especially when allowed to grow over the winter and into spring. Like other legumes, it's important to mow or cut before it goes to seed. Its fragile seed pods shatter easily, which can lead to it regrowing as a weed later in the season. USDA Growing Zones: 3-10 Sun Exposure: Full sun to partial afternoon shade Soil Needs: Prefers well-drained, slightly acidic soil with high fertility Partridge Pea (Chamaecrista fasciculata) Steven Autry / Getty Images Partridge pea is a short-lived perennial plant that is grown as an annual for use as a cover crop. It's often used as an trap crop to attract predators (like wasps) that attack and mitigate pests (like stink bugs) that feed on other nearby crops. It also provides ground cover and food for quail and other game birds. Like clovers, it's a source of nitrogen, and is also considered a great erosion control species. USDA Growing Zones: 3-9 Sun Exposure: Prefers full sun, will survive shade Soil Needs: Prefers sandy or slightly loamy soil; requires little water Okra (Abelmoschus esculentus) Chunumunu / Getty Images Okra might seem like a strange choice for a cover crop, but it's catching on among with farmers who are willing to experiment. This flowering plant is mostly grown as an annual vegetable crop thanks to its edible seed pods, but its fast growth and drought tolerance makes it a perfect summer cover crop, as well. It has long tap roots that help break up compacted soil and retain valuable moisture. That you can harvest it for food all summer before cutting it down to mulch your fields is just an added bonus. USDA Growing Zones: 2-11 Sun Exposure: Full sun Soil Needs: Moist, fertile, well-drained soil, prefers neutral pH soil Mustard (Brassica napus) Peter Olsen Photography / Getty Images Mustard is a cool-season spring annual that makes a good cover crop thanks to its chemical makeup. It is high in glucosinolates, compounds with a biofumigant response that helps repel common pests that plague a number of common vegetable crops, including potatoes, onions, peas, and carrots. Mustard matures in 80 to 95 days, and should be mowed or cut when it begins to flower. It's best to incorporate the cut forage into the soil immediately. USDA Growing Zones: 4-11 Sun Exposure: Full sun or partial shade Soil Needs: Adapted to fertile, loamy, well-drained soils; tolerates variable soil types that drain well Cowpeas (Vigna unguiculata) Maria Dattola Photography / Getty Images Cowpeas, also known as black-eyed peas, are an annual legume that is used as a cover crop because of its deep taproots and its role as a nitrogen source. It's a summer crop that grows well in across the eastern United States. Though you can find bushy varieties, the taller, vining types are better suited as cover crops. Cowpeas are often used as a companion crop to corn, which thrives in similar climates. USDA Growing Zones: 2-11 Sun Exposure: Full sun or partial shade; can get moldy if overshaded Soil Needs: Slightly acidic, fertile, well-draining soil; add organic matter to poor soil if possible Common Oat (Avena sativa) Westend61 / Getty Images The common oat plant has been widely used as a cover crop for many years. This annual grass grows quickly in fall weather, and can be planted directly after the main summer vegetable harvest. In zones seven and below, it will die off over winter. In warmer climates, it can survive mild winters. It works well paired with legume cover crops like clovers, because it will gather soil nutrients that boost the productivity of its companion species. USDA Growing Zones: 2-10 Sun Exposure: Full sun or partial shade Soil Needs: Acidic, well-drained, fertile soil View Article Sources “Sorghum-Sudangrass: A Vigorous Cover Crop.” The University of Vermont. “Cover Crop, Hairy Vetch.” University of Massachusetts Amherst Extension.