LogFAQs > #941069497

InfestedAdam posted...

Reading this topic again just reminded me I need to spray some weed killer again on various parts of my lawn. I poured about a cup on some crab grass and bloody thing is still alive.

Crab grass is in the family Poaceae so weed killers that won't kill grass won't kill crab grass either, and herbicides that will kill crab grass will also kill your lawn. But unlike most lawn grasses, crab grass is an annual, it will die off every winter then regrow from seed. So you can either pull the stuff by hand thus preventing it from going to seed, or you can apply a pre-emergent herbicide in the early spring and late fall which will kill the new plants before they can get established.

I used to have a major problem with sandbur, which is also family Poaceae and thus immune to most lawn-safe herbicides. Applying a pre-emergent over several acres would be extremely expensive, so I just wait until the seed heads begin to form then I pull the plants by hand. I still have some sandbur, but it's much less than it used to be.

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Minutus cantorum, minutus balorum,
Minutus carborata descendum pantorum.