When Should Grass Seed Be Planted With Frost?
- Plant cool-season grasses in either spring or fall, but fall is the preferable time to plant, according to the University of Missouri Extension. You can spread your seed very early in spring, but it will not show good growth until the soil temperatures reach 50 to 65 degrees F. This dormant period won’t cause any harm. In the spring, wait until there is only a thin layer of snow or the snow cover melts away completely, at least temporarily, to spread your seed.
- For fall planting, your goal is to beat freezing temperatures. Cool-season grasses require at least 30 days to become established before frost. While mid-September is the cutoff date for planting in many areas, you can get a better estimate of the last planting date for your location by researching the first average frost date for your area and subtracting a month. At temperatures below 50 degrees F, these grasses become dormant, and as temperatures trend lower, the possibility of a freeze increases. If you plant it too late, your seed may germinate poorly, slowly or not at all.
- In the fall, mow your lawn down to a height of 2 inches or less and remove accumulated thatch if there is a layer sufficient to block the seed from reaching the soil. Apply a layer of mulch -- straw works well -- to help protect the seedbed from an unexpected drop in temperature. Your grass must grow enough to feed its developing root systems. Too-young plants may not harden off properly or be able to survive dormancy.
- When seeding pasture, cut the cover down to 2 inches high. This reduces competition for your seeds. The low cover, spring rains, freeze-thaw cycles and the presence of animals on the pasture will all help bring the seed into better contact with the soil. While the timing of planting varies by location, it is usually done during the late-winter months from February to mid-March.
- Frost seeding is used to introduce forage legume species into grassy pastures or to plant cool-season grasses. Legumes offer additional nutrients when mixed with pasture grasses, making the forage more palatable and digestible, improving growth rate and milk production and improving reproduction in animals, according to the Ohio State University Extension.