Effects of Multiple Mowing on Western Ironweed (Vernonia baldwinii) and Gray Goldenrod (Solidago nemoralis)

Abstract

Western ironweed (Vernonia baldwinii Torr.) and gray goldenrod (Solidago nemoralis Ait.) were mowed at various frequencies during two growing seasons in two experiments for each species. The initial mowings were made in late May or early June when rapid growth was taking place, presumably at the expense of carbohydrate reserves and also on June 15 and July 1. Subsequent mowings were made whenever the weed regrowth had reached 15 to 20 cm. The greatest reduction of western ironweed occurred with multiple mowing when the initial mowing was made on May 20. The degree of control was less in the second experiment than in the first. Multiple mowing was highly effective for reducing the stands of gray goldenrod; but in one of the two experiments, single mowings per season were almost as effective as multiple mowings.