Needed lime should be applied one year ahead of seeding if possible. Phosphorus and potassium can be applied ahead of or at the time of seeding. Nitrogen should not be applied in the fall before or during the year of frost seeding because it will stimulate the growth of the grass and weeds and make them too competitive with the new seeding. All commonly grown legumes can be frost seeded. Red, Alsike, and Ladino clover have greater seedling vigor and establish more quickly than do alfalfa, birdsfoot trefoil, and crownvetch.
Red clover is the most widely used in frost seeding and has proven to be good in establishment.
Clovers are better suited than alfalfa to soils that are not well limed and are somewhat poorly drained. Seeding rates should be equal or somewhat higher than those used for prepared seedbeds. An Eastern European clover, Kura clover is now being researched and demonstrated at several Iowa State University research farms and shows some promise as a pasture forage. It produces about the same as red clover but is a perennial and spreads by underground stems called rhizomes. Right now, the seed is somewhat expensive but you might keep an eye out for it.