Quackgrass

Asked May 1, 2013, 10:38 AM EDT

I have a quackgrass problem in my lawn. I would estimate that 50% of my lawn has been taken over by quackgrass, some areas higher and some less. Over the past few years, I have tried to strengthen my lawn, by aerating in the fall, dethatching, mowing frequently, and fertilizer treatments. These measures have only seemed to make the problem worse. I know there is no selective herbicide for this problem. What are my options? Should I round up the whole lawn and start over? Thanks, Ben

Story County Iowa

1 Response

There are basically two options in regards to quackgrass in the lawn.

One option is to tolerant the presence of quackgrass in the lawn and do nothing.

The other option is to destroy the quackgrass and then reestablish the lawn. Unfortunately, quackgrass is very difficult to destroy.

Quackgrass is a cool-season perennial grass. It spreads rapidly by underground stems or rhizomes.

To effectively control quackgrass, all of the rhizomes in the soil must be completely destroyed. Any rhizomes (or parts of rhizomes) that remain in the soil will eventually root and produce leafy growth. Quackgrass can be destroyed by applying glyphosate (Roundup). However, it will likely take several applications. To make sure the quackgrass is completely destroyed, spray at least 2 foot beyond where quackgrass is visible. The plants should die within 1 to 2 weeks of the application. When new quackgrass shoots emerge, spray again. Continue to do this over a period of 4 to 5 months. If control efforts were begun in May, it may be possible to reestablish the lawn in fall.