Master Gardener: Lawn renovation

September is a great time to renovate poor quality lawns. Renovation is the last step before replacement.

Replace lawns that contain more than 50 percent weeds. Starting over gives you quicker and more effective results. Kill the existing lawn and reseed or sod.

Early to mid-September is the best time to plant grass seed. The warm soil speeds up germination while the cooler temperatures aid in growth and development. Later plantings do not have time to establish and may be winterkilled.

If renovating the lawn, cut the grass as short as possible and rake off clippings. Remove the thatch layer if it is more than ½ inch thick. Core aerate compacted soil to improve drainage.

Spread grass seed over the renovated area using a broadcast or drop-type spreader. Use 3-4 pounds per 1000 square feet of sunny grass-seed mixes or 4-5 pounds per 1000 square feet for shady mixes. Apply half the total amount in one direction and the remainder at right angles to the first. Rake for good seed-to-soil contact.

Water new plantings often enough to keep the soil surface moist. Reduce watering frequency once the grass seeds have sprouted.

Fertilize renovated lawns in October. Cut the grass once it reaches 4 inches with the mower set at 3 to 3 and ½ inches high.

Fall is the best time to control perennial weeds, such as dandelions and plantain.

Control violets in the lawn with a broadleaf weed killer containing triclopyr. Make the first application in mid-September. Repeat in late October if weeds are still present.

Wait to treat Creeping Charlie. Late fall applications, after a hard frost, of broadleaf weed killers will kill this weed. Do not be alarmed if the weed begins to grown next spring. Fall-treated Creeping Charlie often starts to grow, but quickly dies. Keep in mind there are hundreds of seeds just waiting to sprout. It may take several years to get this pest under control.