Field bindweed (Convolvulus arvensis) is a common problem in Colorado lawns. Bindweed and other common weeds don’t like the competition they face in a dense, healthy, well cared-for lawn. But this deeply-rooted perennial member of the morning glory family will quickly take over the unhealthy, malnourished lawn, or those lawns suffering from drought stress or poor irrigation coverage.
The first steps towards controlling bindweed in lawns include providing adequate nitrogen fertilization (2-4 applications during the year, depending on turf species and age of the lawn), timely and uniform irrigation, and mowing the lawn in the range of 2½ to 3 inches. These practices alone can substantially, over the course of a couple of years, reduce the amount of bindweed in a lawn. Bindweed can be more quickly controlled when proper management is combined with judicious herbicide use. Pre-emergence herbicides are useless for controlling bindweed. Because of its very deep and extensive root system, systemic post-emergence products must be used.
Bindweed survives many herbicides that kill other plants. For example, 2,4-D is largely ineffective against bindweed if used alone. Three-way mixtures containing dicamba or dichlorprop (combined with the standards 2, 4-D and MCPP/MCPA) can provide moderate to good control.
The herbicide quinclorac is highly effective at controlling bindweed. Quinclorac is also a component of a few professional products. Quinclorac is available to the homeowner in the products Ortho Weed B Gon MAX plus Crabgrass Control and Bayer Advanced ™ All-In-One Lawn Weed and Crabgrass Killer. Remember that these herbicides are labeled only for use in lawns and can’t be legally or safely used in landscape beds or vegetable gardens.