Sweet clover is a slow-growing biennial often used to alleviate compaction. Sweet clover does not flower in the year of establishment. In the spring of the second year, it grows quickly to become a tall, coarse-stemmed plant. The presence of coumarin in sweet clover makes it less palatable to livestock.

There are two types: white-flowered and yellow-flowered. White sweet clover is deeper rooted, taller and coarser, which makes it more suitable for plowdown than forage. The yellow-flowered is more palatable to livestock and more attractive to bees. Mouldy sweet clover hay may contain disoumarol, which can prevent normal blood clotting and result in the death of livestock from bleeding.