Flowering is induced when day length exceeds 12 hours. Crimson clover reseeds well if allowed to mature and if sufficient moisture is available. Many varieties have high proportions of hard seed. Environmental preferences and limitations Crimson clover does not survive extreme heat or cold and grows best in cool, humid weather. It cannot endure much drought and does not do well on poorly drained soils.
Moist soil is essential for germination and establishment.
Crimson clover is adapted to soils of low fertility and has an intermediate lime requirement. It can tolerate pH ranging from 4.8-8.2 but does better at pH closer to 6.5. Crimson clover is moderately shade-tolerant. It often is used as a winter annual cover crop in annual rotations. It has been used successfully in reduced-tillage farming systems, and in orchards and vineyards where it can be managed to reseed itself.