Northern lawns grow best with cool-season grasses, like Kentucky bluegrass, fine fescues and perennial ryegrass. Because those turf grasses grow rapidly when temperatures dip to more comfortable levels—usually around 65-85°F—prime time for growth in many states usually starts in late August or early September. That’s also the time to establish new cool-season lawns so that newly seeded grass will have time to take root before the frosts of winter.
Use the following guidelines to help set the agenda for your cool-season lawn this autumn. Not growing cool-season grasses in your yard? Check out our article on autumn lawncare for the South instead.
Most lawncare experts will tell you that, if you only fertilize cool-season lawns once a year, September is the best time to do so. One goal for autumn fertilizing is to prepare in advance of the harsh winter months by encouraging your grass to grow dense, long roots. Use a fertilizer like Scotts WinterGuard to promote more active growth and restore the nutrients that were lost during the long months of summer heat. A last application just before winter starts in earnest will provide your lawn with reserve nutrients to help it green up more quickly next spring. Make your last application no later than mid-November, and as early as Halloween in regions where the temperature drops quickly.
If summer took a greater than usual toll on your turfgrass this year, judicious overseeding can go a long way toward rejuvenating your lawn. First, make sure you’ve treated the cause of any problems not directly related to the heat—applying more seed to a diseased or insect-infested patch of lawn likely won’t help matters. Once you’ve eliminated the cause of the problem, you can overseed to fill in thin or bare patches. Mow the area to a leaf length of about 1in to give new seeds a fighting chance. If the soil is densely compacted, use a power rake or core aerator to break up the thatch and sod. A motorized or hand-operated seeder can help you distribute the seed evenly. Be sure to water immediately after overseeding, and regularly thereafter to help stimulate growth.
The changing colors of leaves may be beautiful, but can pose hazards if allowed to accumulate in your yard. In addition to blocking the sunlight your grass needs for photosynthesis, drifts of fallen leaves can also provide the sort of dark, damp habitat where turf diseases incubate and grass pests lay eggs. For a light scattering of leaves, you can mulch them directly into your lawn by mowing them into bits too small to catch with a rake. For a heavier accumulation of leaves, you’ll need to break out the rake. While you’re at it, get some use out of what you’ve gathered with these ideas for using collected leaves.