Frost seeding is viewed as a low-cost method for livestock producers looking to renovate pastures while increasing yields and improving quality with little commercial nitrogen.
Frost seeding involves broadcasting a grass or legume seed over a pasture and letting the natural freeze/thaw cycles of late winter and early spring move the seed into good contact with the soil. The best time to frost seed is usually from mid-February to the end of March.
“A basic requirement for frost seeding success is to make sure that the sod cover has been opened up, and that there is not much growth present to prevent the seed from coming into contact with bare soil,” said Rory Lewandowski, Ohio State University Extension educator in Athens County.
Generally, a pasture is prepared for frost seeding by grazing it down hard, although some light tillage or a close mowing could also be used.
Another frost seeding method involves combining frost seeding with hoof action, said Lewandowski. Under this seeding scenario, let your animals graze the paddock in early March to scuff up the soil and open up bare areas in the sod. At this point, broadcast the forage seed across the paddock. Keep the animals in the paddock another couple of days and let them continue to graze and trample or hoof in the seed.
This method seems to work best with sheep because they don’t trample the seed into the soil too deep.
In general, legumes tend to work better for frost seeding compared to grasses, said Lewandowski. This might be because legume seeds are typically heavier than grass seeds and can reach the soil level more easily.
Another advantage to frost seeding a legume is that legumes ‘fix’ nitrogen typically in excess of their own needs. The existing plants use the excess nitrogen, which improves their quality as a feedstuff. Once legumes become established in a stand of pasture and compose 25 percent to 30 percent of the stand, there is really no need to apply supplemental nitrogen.
The following are some of the more popular legumes used for frost seeding:
Although grasses do not generally work as well as legumes, research has shown that perennial and annual rye grasses and orchard grass are suitable for frost seeding.
For information on improving pastures with frost seeding, refer to the fact sheet on OSU Extension’s Ohioline.