Question
I live on Long Island. In May I added topsoil to my front yard to raise the overall level because of a newly installed driveway and Belgian block. At the time I added the soil I rototilled the existing lawn, racked it out and seeded. I think I both seeded to late and did not provide enough water- the end result being much of the lawn (the areas which received the most sun) was over run by crabgrass. Would you advise seeding these crabgrass areas now and then applying a pre-emergent in the spring?
Is it to late to applied the seed? Should I rent an overseeder or some other equipment to make sure the seed gets into the soil?

I also have a pretty bad mole problem which I never had before. IS this just a coincident or did I do something to cause this?

Thanks for your help,
Matt

Answer
Soil temperature is the most important factor for establishing a new Lawn, not only because you want to optimize your germination rates, but you want to minimize interference from unwanted visitors.  This is for one thing not the ideal time to plant Seed, and you'll risk Winter kill if you do.

As far as Weeds, it's the Soil temps that trigger Crabgrass Seed to sprout.  New Lawn beds are always vulnerable because more Soil is exposed to the Sun's rays, and heats up faster.  The magic number for Crabgrass: 73 degrees F (although there's no shortage of research on variations).  That's just the kind of conditions that favor Weeds, much more than a regular Lawn, where Grass plants are tightly packed; Soil stays cool and hostile to Weed seeds.  Remember that Crabgrass that germinates late in the Summer has its own problems; it's wiped out by frost.

Recent studies suggest that many Weeds, including Crabgrass, do more than take up space and compete for nutrients/light.  Their roots and their leaves (significant when you consider all that ANNUAL Crabgrass) secrete toxins that weaken competitors and make it harder for you to grow Grass in the same Soil.

I would not re-till this plot, because you don't want to bring any more Weed Seeds to the surface for next Spring, and you don't want to ruin the Soil structure any further.  Amend it generously according to the results of your Soil test.  Then re-sow in the Spring, mow carefully and diligently, and take it easy with the chemicals, especially Nitrogen -- you don't want to push the Grass too hard for its own good and open up tissue to an opportunistic Fungus.  After all, you've worked too hard on this already.  Pay extra attention to Grass growing near the Belgian block; those sections will warm up sooner, making them prime targets for early Weeds.  Just don't blink.

THE LONG ISLAND GARDENER