In addition to operating a dairy farm, Paulie Drexler and her husband keep four acres of spruce, pine, and fir, which they sell as Christmas trees. Weeds that grow between the trees are usually kept under control by mowing or application of herbicides. Mowing, however, requires gentle terrain, and wide spacing between the trees, while application of herbicides is costly, time-consuming, and may, if not done properly, cause damage to the trees. Ms. Drexler was looking for alternative means of weed control, and hit upon the idea of rotationally grazing sheep among her trees.
She divided the Christmas tree plantation with temporary fencing. She rotated her sheep through the plantation section by section, keeping them in each long enough to oblige them to graze down the more unpalatable weeds, but moving them on before they began to browse the trees. Whenever forage became limited, she removed the sheep to an adjacent hay field.
Ms. Drexler reports that the experiment worked very well. Weed control was excellent, the trees were manured in the process, and Ms. Drexler obtained, in the form of the sheep, another source of income. She observed only very slight damage to her trees, but never to the spruces, and only if the brush was allowed to grow too long and fibrous.