"JL" wrote:
I had a section of lawn that had crabgrass in years past.
This spring I used a product that contains Dimension (thanks ahlg).
It worked great. I have some stray crabgrass plants
that I deal with spot treatment.

Will I ruin my Dimension for next year if I de-thatch
this fall/next spring? That is, how long do I have to
wait for the crabgrass seeds to finally die before I'm
able to dethatch?

De-thatch this fall, then apply dimension again next spring. What's the
question?