Bromegrass Killer

Asked April 6, 2015, 7:10 PM EDT

What will kill bromegrass in an iris and poppy flower bed? Thanks!

Shelby County Iowa

1 Response

Controlling weedy perennial grasses in flower beds is difficult. Brome grass spreads via underground stems or rhizomes. The rhizomes have to be completely destroyed in order to control brome grass. Any portion of a rhizome that remains alive will eventually sprout and develop into a plant.

Selective applications of glyphosate (Roundup) is one control option. During the growing season, periodically apply Roundup to the brome grass with a foam-type paintbrush. Dip the paintbrush in the Roundup solution and then dab it on the grassy weed. When applying Roundup, make sure that none of the herbicide gets on the iris or other desirable plants.

Digging is another option. When digging, remove as many of the grass’s rhizomes as possible. Dig up the area again when new sprouts appear.

Patience and persistence will likely be needed as it may take one or two years to control a weedy rhizomatous grass, such as brome grass.