The Grass Doctor

I put down scotts crabgrass preventative, how can I reseed the spots it kills?

Got the turfbuilder with halts crabgrass preventative, but the bag said not to reseed after using it. So, it kills the crabgrass, but how can I fill those spots with grass so crabgrass or other weeds don't come back? with When can I seed again?

Public Comments

1. Your best bet will be to check the bag, or the website, to get the exact amount of time that preventative lingers. It's probably something like 4 months and about a month if you want to put sod in the dead spots. Crabgrass preventitive doesn't actually KILL crabgrass, it just prevents seeds from germinating. In other words, it won't create a dead spot in your lawn, but it will keep a current dead spot dead. Crabgrass is an annual plant, so in my zone 5/6 lawn, all of the crabgrass from last year is dead and applying the Halts would keep the seeds from germinating this year. It would also prevent most other weed seeds as well as grass seed from germinating. Having said that, if you have crabgrass already alive and growing in your lawn, you can put down the Halts, but you are just minimizing the problem this year rather than solving it. Then this fall, which will be long enough for the Halts to stop working, make sure you do your seeding and get the good grass established before winter. Then next spring, get the halts down and the grass PLANTS will fill in the dead spots that crabgrass filled this year. (And, if you are in a zone like me and you have grassy weeds growing in your lawn that look like crabgrass, it isn't crabgrass. It is probably a perennial weed, and a much nastier problem than crabgrass.)