How do I get rid of crabgrass?


Spring was very late and I missed the window for putting down crabgrass preventer. I have a lot of it. It's already September and in the 90s again. Should I let it die off on its own? I want to aerate, scarify and reseed this fall, later this month. Any ideas? Am I wasting my time? Thank you.

  5 answers
  • Gary Efanti Gary Efanti on Sep 02, 2018

    If you try to kill crabgrass this time of year it will be uglier than leaving it alone. Or cutting it out now in 90 degree weather is even more tedious and probably leave gaping brown spots until everything comes back to life. However Aeration and overseeding will improve your lawn for next year. Just be sure to apply the pre-emergent or crabgrass control in early spring. Watering will help immensely as well in high temps. Just try watering early morning preferably if possible. This will allow the lawn to actually absorb the water better all day. Watering at night is OK but can lead to fungus and other lawn diseases from "wet feet" of the roots. However if that's your only time to water, it's better than no water at all. Even a couple times a week will help your lawn's root system get stronger and survive the temperature fluctuations we have here in the northeast better. It doesn't have to be watered every day. Sometimes this can cause shallower root systems and they will get too used to the water every day and brown out quicker once you stop. I hope this helps.  Good question though!!

  • Mary Thorne Mary Thorne on Sep 02, 2018

    Thanks Gary! It helps a lot. I was afraid if I applied Quinclorac now, I'd have to deal with a lot of dead crabgrass and it would look pretty bad. Have a good weekend and enjoy the fall. This summer has been pretty bad on the lawn.

  • Thelma Thelma on Sep 02, 2018

    Hi, If you're going to reseed this fall, spray the entire area of crabgrass with 2-4-D weed killer right now. It is a selective weed killer that kills weeds but not grass and the crabgrass will NOT die, it only hibernates during the winter and comes up from the roots the next spring. It must be killed - roots too - before planting or reseeding an area. If the roots are not killed, the crabgrass will take back over the next spring. Good Luck!!

  • Mona Blake Mona Blake on Sep 02, 2018

    You have to kill it off before areating and seeding or you will multiply it! You can put down crab grass killer on any still day right now. Reapply in 7 to 10 days.

  • Jewellmartin Jewellmartin on Sep 02, 2018

    Keep your lawn mowed now when the hot temperature encourages weeds and kills grass. Water deeply about once a week. At the end of Sept. or even October, scalp the lawn, aerate the turf, and apply the weed preventer. You may want to plant some winter grass, but it is not good for your regular lawn. But it’s a choice. Best wishes, Mary. ☺️