Crimson clover (Trifolium incarnatum) is the most important winter annual legume of the central section of the Eastern States (fig. 1). Besides being an excellent hay plant and furnishing an abundance of early spring pasture, it affords protection to the soil during the fall, winter, and spring, prevents soil washing, and provides green manure for soil improvement. This legume has the distinct advantage of being a heavy producer of seed, which can be easily harvested and sown without the use of expensive machinery.

Crimson clover is a native of Europe and is widely grown in France, Hungary, and other central and southern European countries. Seed was introduced into this country as early as 1819, but it was not until 1880 that the plant became of agricultural importance. During the last 6 years the annual commercial consumption of seed in the United States has ranged from 2 to 4 million pounds. In addition, large quantities of home-grown seed are used and handled from farm to farm.

The common name of this clover is derived from the distinctive bright crimson color of the blossoms. Other common names, such as German clover and scarlet clover, are frequently heard in different localities. In general the leaves and stems of crimson clover resemble red clover, but are distinguished by the rounding of the tips of the leaves and a greater covering of hair on both leaves and steins. When it is planted in the fall the leaves develop from the crown and form a rosette, which enlarges whenever weather conditions are favorable. In late spring flower stems develop rapidly and terminate their growth with elongated flower heads. Seed forms and the plant dies with the advent of hot summer weather. The seed is yellow, slightly larger, and more rounding than red clover seed.