If crabgrass is taking hold in your lawn this summer, now is the time to act. Grassy weeds like quackgrass, crabgrass, tall fescue and bromegrass are common invaders in Colorado lawns.
They spread by seed, and have a nasty habit of growing in large, thick clumps. The best control is an herbicide, but it will also kill the lawn grass with the weedy grass. Dead sections can be reseeded or sodded.
The overall best prevention is to keep a healthy, well maintained lawn. Regular mowing, watering, aerating and fertilizing keeps lawn grass thick, with little room for any invaders.
If all else fails, try applying pre-emergent again in the spring, before seeds germinate.
Originally published on July 7th, 2011. Updated on April 30th, 2019.