Answer: If you used a pre-emergent crab grass killer, it will prevent your desired grass seed from germinating as well. Be sure to read and follow all of the directions on any lawn product you use.
It is always a challenge to get lawn grass up and growing before the crabgrass takes over. Crabgrass is an annual, while the lawn grasses are perennial. As your lawn becomes healthier it will crowd out the crabgrass.
Keep in mind also that each time you disturb the soil you bring more weed seeds to the surface where they can germinate. Here is some additional information on lawn weed control you may find helpful.
Good luck with your lawn this summer!
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