Crimson clover was first used in the U.S. in the south as a pasture legume. Its use began as early as the mid 1800s and interest in using it increased around 1940. Over the past 60 years, many different types of crimson clover have been produced. Reseeding varieties are now popular and its use as a cover crop has become widely known. Crimson clover has many benefits that can be an asset to a farming system.
Crimson clover is a legume, meaning it adds to the nitrogen pool through N fixation. It also scavenges for N in the soil, and produces around 70-150 N pounds on average. It grows quickly and is robust once it's established. This make it ideal in providing quick or early N to fields that are in need of N.
Crimson clover's root system helps prevent erosion and builds soil. It prevents nutrient runoff and allows more precipitation to go into the soil. This builds the soils for future crop systems. Crimson clover is also a nutrient scavenger, so it brings up nutrients from deeper in the soil.
Crimson clover also offers good grazing in cattle. It can be grazed before flowering and still produce good N. Watch for bloat when grazing cattle on crimson clover.
The cover also offers elongated, deep red blossoms to beneficial insects such as bees. The blossoms are 1/2- to 1-inch in length and produce lots of nectar. It also serve as a habitat for beneficial predators.
Like all cover crops, crimson clover has specific management needs to ensure a good, reliable stand. While it grows well in any type of well-drained soil, it prefers sandy loam, and has a poorer performance in heavy clay, waterlogged soils. It also performs poorly in highly acidic or alkaline soils. This type of clover prefers to grow in soils with a pH of 5.5-7.0. If soil pH drops below 5.0, it can shut down N-fixation done by the clover.
Crimson clover grows well in mixtures of small grains, especially oats. It can also be mixed with other clovers or medics. For mixed seeding, sow crimson clover at about two-thirds of its normal rate. In order for crimson clover to reseed itself, there has to be sufficient moisture through April.
For winter annual use, crimson clover should be seeded 6-8 weeks before the first average frost date. If using a drill, seed at 15-18 pounds per acre; if broadcasting, seed at 22-30 pounds per acre. For summer annual use, plant as soon as the danger of frost has passed. Seeding rates are similar to winter seeding rates. Crimson clover can be over-seeded in crops such as corn and used after short rotation crops such as snap beans.
The clover will winterkill. If it survives through the winter it can be terminated mechanically. Mowing after early bud stage will effectively terminate the clover.
Crimson clover works well with crops sown in the late spring, or harvested in early fall. Crimson clover also works in a strip-tilling system.