Overseeding After Applying Crabgrass Control
I took the opportunity to put down a pre-emergent crabgrass control plus fertilizer two weeks ago. The instructions said that you need to wait six weeks before doing any overseeding, or applying any grass seed (which I need to in some areas of my lawn), so I wanted to get it down as early as possible. Now what?
Many gardeners need to control the weeds and reseed bare areas. We usually wait until the soil temperatures are 55 to apply crabgrass pre-emergent. This is about the time the vanhoutte (bridal wreath) spirea bloom and the lilac buds begin to swell.
This way we get the product down just prior to the crabgrass seed germinating but we also get the longest period of control. This is important since crabgrass seed continues to germinate throughout the spring.
Early applications do not provide control of the late sprouting seed. Wait the recommended period before seeding your lawn. Late August through mid September is the best time to sow grass seed.
In the meantime keep the grass tall and water thoroughly and as needed for a healthier lawn that is better able to crowd out crabgrass.