The time of the year when frost seeding is most effective in Ohio will not be here until February or March. However, now is a good time to start preparing and determining which paddocks will be seeded.
If the areas you intend to frost seed currently have poor grass/legume growth, the first thing you need to determine is why the problem has occurred. Soil tests should be taken if sampling has not been done recently in the areas you plan to seed.
Adding more seed to soil that lacks proper nutrient levels or has a pH that is too low for the intended crop is not going to grow more of the desired forage if you just broadcast more seed.
Or, the situation maybe also be that nutrients are sufficient, but the pasture is not being managed properly for the plant species you desire.
Smaller seeds. Frost seeding typically works best with legume seeds because it is easier for smaller seeds to drop to the soil surface and make contact than it is for the larger, lighter grass seeds.
Areas you plan to frost seed should not have large amounts of undecomposed plant material remaining in the field. If it does, put animals in those areas now and allow them to graze the area closely. Removing this plant material will make more openings to allow seeds to fall to the ground.
If frost seeding is going to be done in areas that are predominantly fescue, planning for livestock to be in those areas when the ground is soft, some time between now and seeding time, may be beneficial to help open the soil and make more places for seed to contact the soil.
Making a muddy mess of any area to be seeded is not the goal, but if weather conditions are such that livestock are going to trample an area this winter or spring because you do not have a heavy-use feed pad to put them onto, the sacrifice area may as well be where you plan to frost seed.
One can use this method to renovate pastures, improve stands, or alter the species mix within a pasture. Producers should remember, however, this is only a means to help get the seed in good contact with the soil.
Nutrients. Adding nutrients should be based on the soil test recommendations to achieve desired results. Encouraging legume growth in pasture fields can help minimize production costs by reducing the amount of nitrogen fertilizer necessary for maximum forage growth.
Stands that contain approximately 30 percent legumes generally need no additional nitrogen added.
Legumes also improve the quality characteristics of a grass stand. Frost seeding offers several potential advantages when properly implemented.
These may include: establishment of forage in undisturbed sod; reduced labor; less cash expense compared to conventional tillage methods; the ability to establish forages with minimal equipment investment; and little, if any, “nongrazing” period.
The reason February or early March are good times to frost seed pastures in our area is because of the repeated freeze and thaw cycle of the soil at this time of the year.
This is needed for seeds that are broadcast to obtain good soil-to-seed contact. Good contact is necessary if seeds are to grow and compete with established grasses, other legumes or weeds.
Don’t seed before a heavy rain or when there is much snow on the ground. Large portions of your seed may be washed away from your targeted area.
Planting mixtures and seeding rates differ greatly. Desired species and number of seedlings wanted in the final stand determine how much to plant.
Rates. As a rule of thumb, if legumes are already present in the pasture, 3 pounds to 4 pounds of red clover and 1 pound to 2 pounds of ladino or alsike clover seed per acre works well. Birdsfoot trefoil could also be used at 2 pounds to 3 pounds per acre.
If no legumes are currently present in the stand or seeding one species alone, doubling the above rates may return better results. Also, remember to inoculate legume seed with the proper inoculum when planting.
Inoculation is especially important when seeding legumes into soils where no legumes have been grown for several years.
If grasses are to be frost seeded into existing pastures, perennial or annual ryegrass, orchardgrass, or smooth bromegrass would be recommended. Perennial/annual ryegrass should be seeded at 2 pounds to 3 pounds along with 2 pounds to 3 pounds per acre of orchardgrass or 8 pounds to 10 pounds per acre of smooth bromegrass.
Advice. When planting, using a spinner-type seeder; do not mix legume seed and grass seed together. Grass seed will not spread as far as legume seed, causing an uneven stand. Make two trips over the pasture and adjust spacing as needed for the type of seed being sown.
Use high-quality seed. There are new varieties of seed available on the market today that have been designed specifically for use in grazing situations and some have much higher yield potentials than many of the old varieties.
When growth begins in the spring, excessive growth of established plants and competition with the new seedlings should be controlled. Frost-seeded pastures should be grazed lightly or clipped in the spring at regular intervals to allow sunlight to enter the canopy so new seedlings are not shaded out.
However, do not allow animals to graze plants low enough the first or second rotations that they ruin the new seedlings before adequate roots are developed.
(The author is an OSU Extension Agriculture and Natural Resources Extension Educator in Monroe County, Ohio. Questions or comments can be sent in care of Farm and Dairy, P.O. Box 38, Salem OH 44460.)