Now is the time to frost seed clover as part of a regular pasture renovation plan. There are several types of clover to consider and choosing the right clover depends on the intended results.
Medium Red Clover is an excellent choice where longer stand life is wanted. Common medium red clover will last 2 or 3 years in most situations. It provides good quality and tonnage. Medium red clover is the most common clover used in pasture renovation. It is faster growing than mammoth and works well in a grazing or haying situation. Regular overseeding will provide a consistent supply of clover for grazing animals. Medium red clover is a good companion with alfalfa if the need is to thicken a stand. Seeding rates are 4-8 lbs per acre when overseeding or in a mix with grasses. Tri-An Brand red clover is an improved variety bred to give better tonnage and longer stand life. Tri-An Brand red clover will consistently out yield common varieties.
Mammoth Red Clover is a perennial than provides good tonnage of quality forage. Mammoth works well where the objective is to supply some forage for the summer while improving soil tilth and adding nitrogen credits. It is commonly referred to as single cut clover because it grows slower, flowers late and usually gets one cut per season. Mammoth also works as a winter cover crop. Recommended seeding rate is 20 lbs. per acre.
Ladino Clover is excellent forage for grazing, especially in combination with other forages. It spreads through stolons and is more winter hardy than red clover. Ladino clover will survive on poorer quality soils better than red clover or alfalfa. It does not provide as much tonnage as medium red clover. It does not survive long periods of drought. When overseeding a pasture, the recommended rate is 1/2 to 1 lb. per acre.
White Clover is an excellent addition to pastures to add feed value and to fix additional nitrogen. It grows close to the ground spreading by stolons. It is highly palatable. White clover will not yield with other clovers, so it should be used in combination with other clovers and grasses to provide adequate tonnage. Seed white clover at 1-2 lbs. per acre.
Yellow Blossom Sweet Clover is a biennial that is commonly used for soil improvement. This clover has a very deep root system that can break up clay soils and add significant amounts of residual nitrogen. It is less palatable than other clovers, so use in pastures is not common. It will survive in low fertility soils, but requires a pH of 6.0-7.0. An issue when using yellow blossom sweet clover in a rotation is that it is a host to soybean cyst nematode. Seeding rate for soil improvement is 8 lbs. per acre.
All clovers can cause bloating. Whether haying or grazing, forage grasses need to be a significant portion of the field to avoid bloat. Clovers will germinate at very cool soil temperatures (38◦-42◦ F.) The very small seed size makes frost seeding of clovers an easy way to increase the clover stand in existing fields of grass or alfalfa. To properly frost seed, broadcast the seed when snow cover is off and soils remain frozen. Freezing and thawing cycles common in late winter/early spring will make the seed ready for germination when soils warm and spring rains come.