Crimson Clover as a Cover Crop
Legume cover crop
Crimson clover (Trifolium incarnatum) is a fast-growing annual legume widely used as a cover crop in gardens and on small farms across much of the United States. It is valued for its ability to add nitrogen to the soil, protect bare ground over the cooler months, and produce showy deep-red flower spikes in spring. Gardeners often choose it as a cool-season cover that establishes quickly and fits well into rotations between vegetable plantings.
Benefits
As a legume, crimson clover works with soil bacteria to fix atmospheric nitrogen, which can help build soil fertility for the crop that follows. Its fibrous roots and dense canopy help hold soil in place and reduce erosion from wind and water, while the living cover shades the ground and helps suppress cool-season weeds. As the plants grow and are later returned to the soil, they add organic matter that supports soil structure and biological activity. Actual results vary with your soil, climate, and management, so your local Cooperative Extension office is the best source for site-specific guidance.
When to plant
In most regions with mild winters, crimson clover is planted in late summer through early fall so it can establish before cold weather and grow again in spring. In colder areas it is often used as a spring-planted or short-season cover instead. It is commonly broadcast or drilled into a firm, prepared seedbed and lightly covered, and general seeding ranges for cover-crop use are available from seed suppliers and Extension guides for your area.
Growing it
Crimson clover prefers well-drained soils and full sun, and it germinates and establishes quickly under favorable moisture. It grows through cool weather, forms a low leafy stand over winter in mild climates, and then bolts and flowers in spring. Keeping good seed-to-soil contact at planting and providing adequate moisture during establishment are the main keys to a strong stand; check with your local Cooperative Extension for regional timing and soil considerations.
Ending the cover crop
Crimson clover is usually terminated in spring around early flowering, before it sets viable seed, to prevent unwanted reseeding. Common non-chemical methods include mowing, using a roller-crimper to lay down and crush the stand, or turning the residue into the soil with a spade, fork, or tiller a few weeks before the next planting. In colder regions, fall-planted stands may partially or fully winterkill, which can leave a natural mulch on the surface.
Best for
Crimson clover suits gardeners and small farmers who want a quick-establishing, cool-season legume to build soil nitrogen and protect beds over fall and winter. It is a good fit for open ground between summer and spring plantings and for those who appreciate an attractive flowering cover that also supports pollinators.
General guidance for US growers. Seeding rates and regional mixes vary; your local Cooperative Extension office and NRCS can help you plan. Page updated Aug 4, 2026.