Controlling Japanese Stilt Grass in PASTURES

Asked August 11, 2019, 8:58 AM EDT

Hi. My pastures are being overtaken by Japanese Stilt Grass. Horses won't touch it. How can I control it without killing everything?

Montgomery County Maryland weed issues

1 Response

Japanese Stiltgrass has a fibrous root system, stems which are erect or reclining and it will root at stem nodes. Its leaves are up to four (4) inches in overall length and one half (.5) inches in width and will present with a white mid vein which divides the leaf into unequal halves. The seed head has 1 to 6 terminal spike branches. A prolific seed producer, each plant will produce up to 1,000 seeds annually. Pre emergent herbicide applications for larger areas are the recommended method of control. The seeds will germinate in late March to early April in the average year, which is before crabgrass. Flowering occurs in late September to early October in this region. Prevention of seed production is the first line of defense in the control of Japanese Stiltgrass for the following year. Wildlife are only marginally interested in this species as a source of food.

Mowing can be used to limit the spread and development of this weed. It must be kept short from the beginning of the season, this prevents seed head formation. This though is the opposite of what we desire for the desired species of turf in most pastures. Chemical control can be accomplished with the use of properly applied pre-emergence herbicides. Pre emergent control of Japanese Stiltgrass needs to be started very early in the season. Remember the early germination of this weed, before crabgrass, and note the rainfall during this period is necessary to activate these products. Control options are similar to that of crabgrass, start early and reapply in wet years. Barricade (Prodiamine) has been applied in research plots in December, March and May provided the highest percentage of control at 86%, with a single treatment in March on the average providing 81% control. All pre-emergent products require moisture to activate. Milestone herbicide is labeled for use in pastures and works to control but will not totally eliminate the Japanese Stiltgrass. When using post emergent products, air temperatures above 65 degrees F have been found to provide the best environment for success. Glyphosate products may be used for spot spraying, remember to use caution as this product will damage desired species of grasses that come in contact with this product.