Ann wrote:
"

What makes you think it's crabgrass? Crabgrass is an annual and is
easily controlled in a flower bed by cultivating with a garden fork a
few times when it's germinating; I've never found it to be hard to
pull by hand even after it's established. It could be quackgrass, in
which case you have to remove all of the root, the smallest piece will
resprout quickly, quackgrass is very difficult to control.
--

Ann,

I have had crabgrass before in lawns and easily killed it with
a spray. This looks similar. However, whatever it is grew very
tall (12 to 14 inches) -- after I sprayed it, I waited for it to die
and most of it did not do so. Since I have never had a major crabgrass
problem before, and the crabgrass was always in a lawn where it never
had the chance to grow, I can't definitely say it is crabgrass. Also,
I would add that when an experienced gardener visited my house on one
occasion, she referred to it as crabgrass. I'll make an effort to
specifically identify the plant, but in the meantime, I would
appreciate any suggestions as to how to control crabgrass or quakgrass.

Thanks,

JD