Lawn weeds

Asked August 30, 2019, 10:31 AM EDT

We have a weed of some sort growing and can't get rid of it. Also we have this broad leaf grass popping up. Can you tell me what they are and how to eliminate?

Oregon lawns and turf

1 Response

Hello,

The grass is tall fescue. It is very difficult to remove one grass from another as the grasses are so similar in metabolism. I am not aware of a chemical that will selectively remove tall fescue from other cool season grasses. You could spot treat the tall fescue with glyphosate (e.g. Roundup) and then reseed the dead patches.

The weed looks like wild violet. T-Zone lawn herbicide would be effective against wild violet or another product with 2,4-D, dicamba, and triclopyr. Per the label for best results, make 1 application in late fall and 1 application again in the spring. Be very careful in the spring as one of the chemicals in the herbicide (triclopyr) can volatilize in warm weather and damage plants that are just leafing out. Also, make sure the wind is not blowing during the application.

These lawn herbicides, such as T-Zone (Glyphosate is not a lawn herbicide - it kills everything), need to be applied uniformly at the correct rate. If the rate gets too high, you will kill your grass. I would recommend hiring a licensed pesticide applicator. Most landscape maintenance companies have one on staff.

Good luck.