Jenny wrote:
We had no snow cover this winter and a warm, dry spring. As a result my
10,000 sq ft of lawn, which was crabgrass-free last year at this time is
literally covered with the stuff--despite our putting down preventer
right a week before the forsythia bloomed.

I'm not talking a clump here and there, but large tracts of the stuff,
and this is despite having thick grass which grows up around it. I
already mow to 3" when the lawn is 4".

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Is it confirmed crabgrass, or could it be quackgrass?? In my area (SW
Chicago area) quackgrass is common on treated lawns as the services
*claim* there's no way to treat it withought killing off other
grasses.

http://www.bachmans.com/tipsheets/la...Quackgrass.cfm