Hello all
Zone 5 - Rhode Island - not coastal.

This spring, I replanted my front lawn (3000 sq ft). I realize the spring
is not the best time to plant, but I had to do it. I top-dressed with a
loam-compost mix. I didn't use Tupersan when planting. Now, in some
sections of the lawn, there are large clumps of crabgrass. There is too
much to kill it with a crabgrass killer. I would like to over-seed the
front lawn again this fall with a high-quality seed. What do I do with the
crabgrass? Should I just kill it will Round-up and start over, or can I
just use the slit-seeder, basically cutting through the crabgrass.

Thanks for your time.