Snow does a great job of hiding overgrazed pastures or high-traffic areas at gates, feeders and water tanks. But frost seeding or over-seeding during this time of year can help "thicken up” forage-deficient areas, says Paul Craig, Dauphin County, PA Extension.
“When seeds are applied to bare soil early in the spring (actually late winter is better), the warmer temps during the day combined with freezing temps at night form cracks and crevasses that eventually cover the seeds and initiate germination. Unfortunately each season and location is different and nearly as many failures are reported as successes,” Craig writes in the Ohio Beef Cattle Letter.
Among the factors to consider is time of year. Fields should be over-seeded when soils are freezing and thawing. In many locations, February is a good time but often March is too late. Deep snow cover is helpful as it limits soil freezing and thawing, while a rapid melt or high winds can move the seed.
“Seed must reach the soil surface, so existing vegetation can limit this movement. Overgrazed or high-traffic areas won’t have the problem as much as trying to get a clover to establish in a well-managed grass pasture,” Craig says. “Legume seeds such as clover or alfalfa are more adapted to reaching the soil surface than light fluffy grass seeds. A few growers have used no-till or even conventional drills to thicken up stands with grass seed more successfully than broadcasting. This practice requires optimum conditions at seeding, especially with a conventional drill.”
Craig says red clover is one crop many growers report as having success with in frost seeding. Many crop producers over-seed wheat fields in February with red clover as a green manure crop. Other clovers such as alsike and Ladino establish fairly well, too. The best success with grass species has been with perennial ryegrass and orchardgrass. Seeding rates vary but are usually similar to rates for conventional establishment. Slightly higher rates (25-30%) are used when over-seeding into areas with less vegetation cover.
Once seeded, modify your management to assist establishment of the small seedlings, Craig advises. Existing vegetation should be clipped or grazed to minimize competition, and animals should be moved sooner to prevent overgrazing of small seedlings. Proper fertilizer and/or lime must be present for optimum development, too. Many growers routinely frost seed their pastures every 2-3 years.
-- Ohio Beef Cattle Letter