Controlling crabgrass

[Phreak]

Clear plastic mulching (solarization) is effective for eradicating crabgrass plants and seed if it is applied during periods of high solar radiation. In California's Central Valley, this means during June to August, whereas in coastal areas the best time may be August to September or May to June when fog or wind is most likely to be at a minimum. Before applying the plastic, closely mow the crabgrass, remove the clippings, and water the area well. It is not necessary to cultivate before solarization, but a shallow cultivation may improve control. Place clear, ultraviolet (UV)-protected polyethylene over the area for 4 to 6 weeks. Shade will reduce the effectiveness of solarization because it limits the amount of radiation. Solarization works most effectively when there is no slope in the land or if there is, the slope has a south or southwest exposure. Temperatures are not as high under plastic placed on a north-facing slope; consequently, control is not as effective. After solarization, do not cultivate the area deeper than 3 inches to avoid bringing weed seed into the upper soil layer. (See the soil solarization publication listed in Reference.)

[Steveo]

No shit? Won't that kill damn near anything that grows?

[Chet Hayes]

Plan A:

Mow Remove clippings Consider cultivation to improve control Water Cover area with plastic Anchor it somehow so it doesn't blow away Leave it there for 6 weeks

or

Plan B:

Spray area with Roundup Crabgrass is dead in a week.

I know which plan I'd go with.

[Norman Bates]

[HWick]

why not use MSMA? You may need to treat two or more times but it works well. it also kills other bad stuff. ??

[Steveo]

Heh, the first frost will kill 100% of it.

[William W. Plummer]

Right. The idea is to kill the crabgrass, and only the crabgrass, before it produces seeds. If you attempt to do this by mowing, be sure you use a catcher to pick up all the clippings and seeds. FWIW, I just use Bonide "crabgrass killer". It took three applications this year but I don't think I'll have to use preemergent crabgrass killer next spring.

Roundup it almost always the wrong thing to use for crabgrass. It kills absolutely everything green and will leave gaping spots in your lawn.

[Chet Hayes]

If you look at the OP, the suggested method of using plastic ground cover for crabgrass was obviously for use in an area where the goal was to kill everything, unless you think grass will survive 6 weeks of being covered by plastic. For that application, Roundup is the best solution.

[LT]

The selective (crabgrass) herbicide works, but as noted multiple applications are reqired. You wind up with some dead spots in your lawn thought cause the CB pushes out the real stuff..... LT