How Cold is Too Cold? The Impact of Cold Weather on Cool-Season Forages

AUBURN, Ala. – With this year’s unusual winter weather of snow and ice, it is important for producers to know the impact this weather can have on cool-season forages.

The majority of cool-season forages can handle sub-freezing temperatures for short periods of time, but they grow best at 55 to 80 degrees F. said Dr. Leanne Dillard, Alabama Cooperative Extension forage specialist.

Effects of Cold Weather

Because cool-season forages can handle sub-freezing temperatures for short durations in this region, the effects of snow and ice on forage quality are minimal.

“Research has shown that forage quality is greater in forages grown at lower temperatures compared with temperatures above 80 degrees,” said Dillard. “When temperatures drop below freezing, plants no longer grow and reduces forage yield, but that has minimal effect on forage quality.”

Typically, there is slower forage growth in any cool-season forage species, even more cold tolerant grasses such as cereal rye, during January and early February.

“Tall fescue and other small grains are generally able to persist through this time period, and will start to grow rapidly once temperatures reach above 55 degrees,” said Dillard.

There are, however, some cases, usually in oats, where extreme cold will kill the forage.

“Ice itself does not have a negative impact on forages,” said Dillard. “However, repeated freezing and thawing of forages can damage plants and reduce forage yield and stand persistence.”

Minimizing the Effects

The best ways to minimize the effects of the cold weather on cool-season forages is to remember to minimize overgrazing and damage to pasture sod.

By putting animals in a dry lot and feeding hay when forages isn’t growing, animals are prevented from continuous grazing of the forages and it minimizes sod damage because of the animals standing around hay rings or feed troughs said Dillard.

“Overgrazing reduces the plant root mass, which contains the carbohydrate reserve needed to help a plant survive during cold temperatures,” said Dillard. “Early planting dates for both annuals and perennials will ensure plants are large enough to withstand the weather. Cool-season annuals planted 2-4 weeks before a cold snap will likely not survive or will have reduced forage yields in the spring.”

It is also important to make sure pastures have the correct soil fertility because it will help reduce stress on plants and it will help them recover from any extreme cold.

Extreme cold weather will affect the forage yield but with proper management these effects can be minimized.

For more information on cold weather effects on forages contact your local Alabama Cooperative Extension Animal Science and Forages Regional Agent.


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