Frost seeding involves broadcasting seed over a pasture area and letting the natural freeze/thaw cycles of late winter and early spring help to move the seed into good contact with the soil. The key is those freeze/thaw cycles where we have frozen soils in the morning with day-time temperatures in the 40’s to thaw soil in the afternoon. In our area, late February through March is generally a good timeframe to consider frost seeding. Broadcast seed while walking the area with a hand-cranked broadcast seeder or use a broadcast seeder mounted on an ATV or as a three-point attachment on a small tractor for larger acreages.
Successful frost seeding depends upon good seed/soil contact. A basic requirement for frost seeding success is to make sure that the sod cover, whether pasture or hay field, has open areas. Remember, this is a renovation technique. Looking down into the field you must be able to see patches of bare soil. If the sod is too thick or there is so much forage growth present that the broadcast seed will not fall onto bare soil you are wasting your time and money. Generally, a pasture is prepared for frost seeding by grazing it down hard, beating it up a bit to get more exposed soil. Some light tillage might also be used to open the sod up and create exposed soil, especially with a hay field to be renovated.
All forage species are not suitable to frost seeding. Small, heavy seeds work best for frost seeding. In general, clovers have the best frost seeding success. Red clover is probably the most widely used forage species when it comes to frost seeding. Red clover has high seedling vigor, is tolerant of a range of soil pH, fertility conditions, and tolerates drought better than white clover. Birdsfoot trefoil, another legume, works for pasture situations, but it is slower to establish. Grasses have less success with frost seeding although among the grasses that are sometimes used in frost seeding, perennial and annual ryegrasses do the best. Orchardgrass can be frost seeded, but success is more limited.
Do not frost seed a grass and legume together in a seed mix. Frost seeding is done by broadcasting or spinning seed onto the field, similar to a granular fertilizer application. Legume seed is heavier than grass seed and gets thrown farther. When grasses and legumes are broadcast in a mix, the usual result is alternating strips of forage. Another tip that many experienced frost seeders use is to broadcast at a half rate in one direction and then the other half in the other direction to get a more uniform stand. Broadcasting is not as efficient as drilling a forage into the soil, so seeding rates are increased. Red clover is generally broadcast at 6-8 lbs./acre, white clover at 2-3 lbs./acre, birdsfoot trefoil at 4-6 lbs./acre, ryegrasses at 10-15 lbs./acre and orchardgrass at 4-6 lbs./acre.
In addition to ensuring good seed to soil contact, frost seeding success can be improved by giving attention to a couple of other factors. If the reason for the pasture or hay field thinning out is due to a soil pH or soil fertility issue, then frost seeding is just a very temporary fix. Make sure that soil pH is 6.5 or higher and that soil P is in the 30-50 ppm (Mehlich-3) range. Soil K should be in the 125 to 150 ppm range. If you are seeding a legume that has not been grown in the pasture or hay field for a number of years, it is a good idea to include the proper bacterial inoculum with the seed to insure that the bacteria responsible for fixing nitrogen becomes associated with the plant roots. Finally, frost seeding will not remedy poor pasture management, it will only be a temporary Band-Aid.
A twist to frost seeding is to combine frost seeding with hoof action. Sheep work particularly well for this method. Let the animals begin to graze down the forage and beat up the sod somewhat. At this point, broadcast the forage seed across the paddock. Keep the livestock in the paddock another couple of days, allowing them to trample in the seed to get better seed/soil contact. This method works best when soils are not saturated.
For more information about frost seeding as a pasture or hayfield renovation method, contact the Wayne County Extension office at 330-264-8722.
The fluctuating temperatures that we continue to experience this winter is a contributing factor to increased incidence of calf pneumonia on some dairy farms. Pneumonia is an infectious respiratory disease that involves several different types of viruses as well as bacteria and mycoplasma species. Environmental factors such as low temperatures, high humidity, poor ventilation and direct drafts on calves are often responsible for pneumonia outbreaks. As our temperatures fluctuate from cold to unseasonably warm, ventilation must be adjusted to keep humidity low, provide adequate air exchanges, prevent drafts and keep calves dry.
Rory Lewandowski is an OSU Extension Agriculture & Natural Resources Educator and may be reached at 330-264-8722.
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