When to Reseed Your Lawn in Zone 5

Reasons to Reseed

• Occasionally patches or swaths of a cool-season lawn in Zone 5 die out for any number of reasons. Disease, too much shade, drought or a poor maintenance regimen with inconsistent irrigation or irregular fertilization can lead to bare spots in the lawn. Often in the areas where the once-thick turf grass grew, a multitude of weeds proliferate. Resist the urge to sow seed in these areas when the summer is hottest and rainfall scarce.

Sowing Time Frame

• The month of September is the best time to scatter fresh cool-season lawn grass seed over an existing lawn in Zone 5. The soil is still warm, but the temperatures are progressively cooler and soil tends to remain moister longer after rains or irrigation. In the northernmost areas of Zone 5, sowing lawn seed can begin in late August, whereas in the southernmost areas it can be extended as late as early October. If the late summer was unusually hot and dry, waiting into the latter half of September may prove best. Seed may also be sown in mid- to late March, but much more attention is needed regarding watering and weed control at that time of year.

Prep Work

• Before scattering seed over the thin or bald spots on your cool-season lawn, conduct some basic preparatory work. Pull or hoe out weeds in the areas you want to sow. While removing the entire weed is ideal, even snapping off the plant at the root helps clear the area so light and irrigation reaches grass seed. Take a firm-tooth rake and scratch the soil in the areas needing seed. This loosens the topsoil to a depth of 1/4 to 1/2 inch and allows more seed to come in contact with soil and avoid the eye of hungry songbirds. Do not lay any pre-emergent herbicide, as the chemicals prevent germination of both weed and grass seeds.

Sowing Insight

• Often, cool-season lawns are a blend of several varieties of grass -- varying combinations of both bluegrass and fescue. Fescue is scattered at a denser rate than bluegrass. Scatter the seed over the lawn areas in 2 directions, the second perpendicular to the angle of the first. Gently rake over the sown area to bring the seeds in direct contact with soil. Irrigate the seeded areas as needed, supplementing rainfall to maintain an evenly moist soil. Dry soil inhibits germination, but too much water causes erosion and washes grass seed away.