Frost seeding is a relatively inexpensive practice that can introduce more legumes, and thus more nitrogen fixation, into many pastures. Below are some answers to frequent questions related to frost seeding.
When should I frost seed?
February is the optimal time for frost seeding in most of Ohio. The goal is to distribute seed while there are a series of freeze-thaw cycles, since that is what increases seed-soil contact for emergence.
Which species and varieties are good for frost seeding?
Clovers are the most common species for frost seeding, and most frost seeding research to establish seeding rate and timing recommendations was performed using clover species. Birdsfoot trefoil is another legume option, and annual ryegrass, orchardgrass, and some other grasses can also be established this way. But, plant establishment from frost seeding is usually higher for clovers than other species.
Can I frost seed multiple species at the same time?
Yes, but be careful to adjust seeding rates proportionally based on your desired species mix.
What seeding rate should I aim for?
Seeding rates vary by species, with white (ladino) clover needing lower seeding rates than other species. A good starting place is 3-4 lb/acre for red clover, 1-3 lb/acre for white (ladino) clover, or 2-4 lb/acre for birdsfoot trefoil.
Where should I not consider frost seeding?
Avoid frost seeding in places where bare dirt was not visible before snow fall; thick stands with tall biomass over winter will prevent seeds from reaching the soil. Areas with dryer, sandy soils may be less suitable for frost seeding since they will have less soil movement with freeze-thaw cycles, which limits seed-soil contact.
What should I do after frost seeding?
If you are planning to graze or feed livestock out on pasture, avoid doing so on newly frost seeded pasture. Young seedlings that are just germinated are particularly sensitive to grazing pressure and compaction due to hoof traffic. Another practice to avoid is making a broadcast herbicide application following the frost seeding. Most herbicide applications are non-selective, so it is best to manage weeds prior to frost seeding or spot spraying to avoid damaging desired forages.
Interested in learning more? Check out this article about frost seeding from our colleagues at the University of Kentucky. Consider reviewing variety trial data from MSU or data from PSU when making seed decisions.