Grassy-Weed Control in Ornamental Beds

Jeff Derr, Professor of Weed Science and Director of Hampton Roads AREC

The following was an inquiry from a homeowner in Virginia.

QUESTION: (Homeowner): "How do I control / eliminate creeping grasses from spreading into my mulched flower beds without killing the neighbor’s grass? I used a weed killer in my mulched beds late last summer and noticed a few weeks later that my neighbor’s turf had some dead areas. The product had killed to the roots and translocated through the stems which, of course, were in his lawn. Hopefully, the area will recover as the grass spreads (that’s why it’s a problem in my beds!) – but my problem is not solved as I am looking for weed control, but not at the expense of my neighbor’s lawn AND neighborly relations! Can you offer a solution?"

ANSWER (Dr. Derr): "For selective control of grasses like bermudagrass and quackgrass in a flower bed, I suggest use of a selective grass-control product such as fluazifop (Ornamec 170 Grass Herbicide, Ortho Grass B Gon Garden Grass Killer, or other labeled product with this active ingredient) or a sethoxydim product (Segment II, Hi-Yield Grass Killer, Bonide Beater II Grass Killer Concentrate, or other labeled formulation). You could cut the creeping grass’ runners at the property line prior to treatment so that this systemic chemical does not translocate back into the neighbor's lawn. Fluazifop and sethoxydim will not injure most broadleaf ornamentals (annual flowers, perennials, woody plants) as well as non-grass species such as liriope, daylily, and hosta. Treat the weedy grass foliage when it is actively growing. Do not allow the spray to contact ornamental grasses.