I'm planning ahead for over seeding this fall. There's a section of my yard that is virtually all Crabgrass.

Does it make sense to pull it all up by hand or use a herbacide before putting down the new seed? I want to ensure the seed makes good contact with the soil. I plan on renting aerator (and possibly a power rake). Wondering if either of those tools would be able to power through the thick Crabgrass and give me enough soil contact.


2 Answers 2


If your lawn is almost ALL crabgrass then glyphosate or roundup is indicated. This is absorbed by the foliage and taken down into the roots where the KILL happens. Takes at least 3 weeks. Perhaps a second application. Read that label 5 times I kid you NOT. That is what they taught us as Pesticide Applicators. Five times!!

Do not spray in any wind, preferable to do in the evening when bees and birds and people are not around, regardless of the MSDS or label instructions. Before application DO NOT MOW. Do not use any other herbicide. The more vigorous the growth the better glyphosate works. Wait until all growth is brown, yellow, black dead.

If you don't wait 3 weeks minimum then any seed you apply will have trouble germinating. Don't worry about aeration, now is not the time. That is for an annual maintenance later once per year!

Then look up the lawn maintenance stuff on this site, quite a bit of it for you to learn and know so this doesn't happen again. Such as mow no shorter than 3 inches! Water deeply allow to dry and do not water again until footprints stay down on your grass. Fertilize 3-4X per year with season appropriate formulations. Again mow no shorter than 3"...ever. Otherwise, you won't ever see me giving others prescriptions for pesticides/herbicides! This is a major bandaid on a preventable problem but works well. Nothing else in my experience will work. Certainly not hand pulling, power rake for thatch...this will just leave roots and crab grass will definitely be able to come back if you are going to use seed. Make sure you grade, roll, rake again, roll before seeding. If you are going to use seeding I'd recommend hiring a grass seeding company to spray the seed and mulch and fertilizer at the same time. Otherwise, consider sod especially in your situation.


It appears that it will be quite a bit of physical labor to pull the crabgrass by hand. It is probably not recommended.

You should go with your plan of renting equipment, something to trim the grass down, and then water the area and use a power rake.

You will need to go deep, and yes, use a herbicide, as the seeds must be all over the soil. No matter what you do, crabgrass will come back and you will need to actively weed the area and other areas of your garden for well over a season.

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