Fall is the season for lawn care because of cool weather and regular rain showers. The cool season grasses in this area love that kind of weather. They put on a nice flush of growth and thicken up while the weeds are mostly dormant so next spring the sprouting weed seeds will have fewer spots to colonize. We have always said to not fertilize your lawn in October. September is the ideal month since the grass will have several weeks of good growing weather to respond to the early fall feeding. Fertilizing in October is risky because the new growth may not harden off well enough before winter arrives. Not too many years ago we used to talk about late fall feeding. I was trained to recite the single best time of year to fertilize is in late fall, two weeks after the last time you mow. But late fall feeding hasnt worked out well. People who manage turf intensively will now apply only a half rate of nitrogen in late fall and weve stopped recommending the practice to homeowners at all. Its hard to get the timing right and if you apply it too late to frozen ground, the fertilizer works more as a pollutant, running off into ground and surface water rather than being taken up by the grass plants. If you didnt fertilize in September wait until late May. Thats the second best time of year to feed your lawn. If your lawn keeps growing in October keep mowing it at three inches tall and hand-pull any weeds like dandelions or plantain. Crabgrass dies with the first frost so you might be able to get some new grass to grow from seed planted now. October is too late for large scale overseeding or reseeding to be reliably successful but you might have luck reseeding the bare spots. Amy Ivy is executive director of Cornell Cooperative Extension in Clinton County. CCE offices may be reached in Clinton County at 561-7450 and Essex County at 962-4810. More information may be found on-line at ecgardening.cce.cornell.edu or by sending an e-mail to a Master Gardener volunteer at askMG@cornell.edu.