Though growing forage during this time of year is not an agenda item in the North, such is not the case in the South.
As such, when winter decides to spread its wrath far below the Mason-Dixon Line, it can be cause for concern for those livestock producers who have planted cool-season forages for winter and early spring grazing.
“The majority of cool-season forages can handle subfreezing temperatures for short periods of time, but they grow best between 55°F and 80°F,” says Leanne Dillard, extension forage specialist with Alabama Cooperative Extension. This winter, snow and cold temperatures are pushing the envelope on optimum growing conditions.
Dillard notes that forage growth is generally slowed for cool-season species during January and February, but that they usually persist through this period. When temperatures rebound to 55°F, growth resumes.
“In extreme cold, plants can be killed,” Dillard says. “This usually happens with oats, which don’t have the cold tolerance of cereals such as winter rye.”
Although the slower growth can reduce yield, forage quality can actually improve when plants are growing under cooler temperature conditions. When plants stop growing during extremely cold temperature periods, forage quality is generally unaffected.
Dillard says the best way to minimize the effects of cold weather on cool-season forages is to not overgraze vulnerable pastures and reduce damage to the pasture sod. This may mean pulling cattle off of pastures and putting them in a drylot where they can be fed hay.
“Overgrazing reduces the plant root mass, which contains the carbohydrate reserve needed to help a plant survive during cold temperatures,” Dillard explains. “Early planting dates for both annuals and perennials will ensure plants are large enough to withstand the weather. Cool-season annuals planted two to four weeks before a cold snap will likely not survive or will have reduced forage yields in the spring,” she adds.
Finally, the forage specialist notes that optimum soil fertility will also aid in helping pastures survive extreme winter conditions.