In September and October, pastures must be managed to insure that desirable grasses and legumes are able to build and store carbohydrate reserves for winter, says Rory Lewandowski, Athens County, OH, Extension educator.
“It is this ability to store carbohydrate reserves and thus keep a root system living over the winter months that distinguishes a perennial plant from an annual plant,” he says. “If root reserves are insufficient the plant may die over the winter. If the plant survives but root reserves are low, spring regrowth and vigor of the plant is reduced.”
Lewandowski says there must be adequate leaf area left after a grazing so that photosynthesis is maximized. Regrowth is slower in fall, but if leaf area is present, photosynthesis still takes place at a good rate.
“Therefore, the mistake of overgrazing is amplified in the fall of the year,” he says. “Depending upon the severity of overgrazing, the plant may not regrow enough and develop enough leaf area to take advantage of sunshine and produce carbohydrates.”
The root is the storage area of carbohydrates for plants with a taproot, including legumes like alfalfa and red clover. For white clover, the carbohydrate storage area is the stolen. Technically, cool-season grasses store the majority of carbohydrate reserves in stem and tiller bases, some in rhizomes and only a little in roots. For example, orchardgrass stores carbohydrates in the lower 3-4” of stem bases and tillers. Tall fescue and bluegrass both maintain carbohydrate storage at the base of tillers as well as rhizomes, so they can tolerate lower grazing or clipping heights than orchardgrass.
For orchardgrass, Lewandowski says to leave 4-5” of growth after a grazing pass. Tall fescue and bluegrass should be managed to leave a 3-4” residual.
“Pasture management in the fall of the year that insures there is adequate leaf area to allow plants to maximize photosynthesis and build carbohydrate reserves will pay off in quicker spring green up and more vigorous spring plant growth,” he says.