The rate at which sweet clover should be seeded varies with the
germination of the seed, the condition of the seed bed, the climatic
conditions of the region, and the method of seeding. Throughout the
humid sections of the eastern United States sweet clover ordinarily is
seeded at the rate of 15 to 20 pounds of hulled seed to the acre. From
12 to 15 pounds should be ample where the seed bed is in good condition
and the seed germinates 75 per cent or more. In Illinois, the western
North-Central States, the Mountain States, and the Pacific Coast States
good stands are generally obtained by sowing 10 to 12 pounds of hulled
seed to the acre. In eastern Washington it is claimed that from 5 to 8
pounds to the acre are sufficient for good stands.
When sweet clover is grown under irrigation, 8 to 10 pounds of hulled
seed usually are sufficient, and from 2 to 4 pounds per acre are enough
when seeded in rows from 2 to 4 feet apart. Of unhulled seed 3 to 6
pecks (24 to 48 pounds) or 20 pounds of hulled seed are usually sown in
the South for pasturage or hay. In any region at least 10 pounds more
of the unhulled than of hulled seed should be sown to an acre. Unless
annual yellow sweet-clover seed is thoroughly cleaned it should be sown
at the rate of 25 to 30 pounds to the acre.