Can One Overseed a Lawn?

Transition Zone Lawns

• Lawn grasses come in two variations. These are warm-season grasses and cool-season grasses. Warm-season grasses grow well in the warmest parts of the country. Cool-season grasses grow well in cooler parts of the country. In between these areas is known as the transition zone. In the transition zone, warm-season grasses grow well in summer and go dormant in winter, while cool-season grasses thrive in winter and die in summer's heat. In the transition zone, cool-season grass may be planted to provide a green lawn in the winter. In summer, the grass will decline in vigor and eventually die, while a warm-season grass will thrive and take over. Ryegrass is a popular turfgrass for overseeding in Bermuda or zoysia grass.

Cons of Overseeding for Winter Color

• Some lawn-care experts warn against overseeding in transition zones for winter color. In early spring when warm-season grasses are coming out of dormancy but cool-season grasses are not yet weakened, the competition between the two grasses can be great. In areas where spring is cool and wet, the winter grass can take over. When summer heats up and kills the winter grass, the summer grass will not be able to take over.

Renovation

• Lawns may also be overseeded to renovate grass that is declining in vigor. Typically when grasses are overseeded because they are patchy and thin, the same type of grass seed is used as already exists in a lawn. Small, patchy areas may be overseeded using a rake to break up the soil. Access to the soil may be achieved in larger areas using a core aerator or a slit seeder.

Post Seedling Care

• After lawns have been overseeded, they must be watered frequently until the new grass reaches maturity. Initially, the water must be applied once or twice daily until the new grass reaches the same height as the existing grass. At this point the watering times may be gradually reduced. Overseeded lawns for winter color need regular mowing, fertilizing and watering just like summer lawns. If winter care is not appealing to a homeowner, he should rethink overseeding his lawn.