How can I get rid of the crab grass in my lawn without killing the other grass?

Question

Thanks for all the answers. Some comments:
1) St. Augustine is NOT tougher than crabgrass. Crabgrass will crowd it out and take over your entire lawn unless you do something about it. (My lawn is St. Augustine which means I don't seed; I use sod for filling in bare spots.)
2) I have tried Weed-B-Gon, but it is not as effective as I would like.
3) I started using pre-emergence Crabgrass preventer this year and I hope it works in the future. The problem here is that the existing crabgrass never dies. I think crabgrass is a perennial weed here so I'm a bit uncertain when pre-emergence should be applied. I think I'll just apply it periodically throughout the year. 4) I live in south Florida which means the growing season is year around.
There is no freeze and no winter for crabgrass to die in.
5) The Bayer crabgrass killer sounds like a good suggestion.
6) I have been pulling crabgrass often, but there is so much of it that it would be a lifetime job.
Any more suggestions?

Answer 1

Go to Home Depot and buy Crabgrass killer from Bayer. You attach it to your hose, and it kills all weeds in your yard, without harming the grass. Remember, if you live in an area where it freezes, Crabgrass dies with the first freeze. The seeds germinate next year, and a whole new crop will come up. Next year, be sure to fertilize with a fertyilizer with a pre-emergent. It will stop the seeds from germinating, and you will have no crabgrass.

Answer 2

It depends on how much crabgrass you have and where you live.

If it's just small amounts, I would suggest just pulling it out manually.

Crabgrass is a summer annual, and it needs 3 fulls days of the ground being 55 degrees in order for the seeds to germinate. Because it is an annual, if you live somewhere that has cold winters and frosts, the crabgrass will die for the winter. If this is the case and you have a lot of crabgrass, I would recommend waiting until it dies during the winter, and seeding the bare patches with grass seed early in the spring.

Remember, if you do use a pre-emergent fertilizer in the Spring, don't seed, because the pre-emergent will stop your grass seed from germinating as well as the crabgrass. Also, if you use the pre-emergent, don't do it too early. I live in zone 6 and everyone here puts their pre-emergent down in March, when the crabgrass doesn't germinate until June!

If you use a liquid herbicide, don't use roundup on your lawn...it will kill everything, including your lawn, and makes the soil suceptible to dieases and you will have a hard time growing grass in those areas.

I have used the Ortho Weed-B-Gon ready to use crabgrass killer, which worked pretty well and didn't kill too much of the turf. However, like I said, you might just be better off waiting until next spring if you can and seeding some good turf.

Good Luck!

Answer 3

Crabgrass is an annual weed, which means that it completes its entire life cycle in one season. It starts brand new from seed each spring, therefore the key to its control next year is here. Use what's called a "pre-emergence" crabgrass killer. This product establishes a short-lived chemical barrier on the soil which kills crabgrass seedlings just as they begin to grow. Timing is important. There are ways to kill crabgrass once it has gained a foothold, but they are much more difficult and require patience.

Crabgrass thrives where summers are hot and very moist. Water your lawn deep and infrequently. Mow often and high. Don't let those seeds grow. You can also apply DSMA, MSMA, MAMA when the weeds are small and easier to control. One or more repeat treatments at 7 to 10 day intervals may be necessary. Go to your local lawn chemical store to pick up any of these.

Patience and diligence will prevail in your situation. Be strong :)

Answer 4

Scotts makes a pre-emergance preventer/fertilizer that you use early in the season. There is also a product called Crabex that will take care of post-emergance crabgrass. the Scotts product is available everywhere, Crabex is hard to find in Canada, but shouldn'y be a problem in the U.S. weed-b-gone won't work because it is a "specific" herbicide made to kill broad leafed weeds. i.e Dandlions, ivy, ect. You need a crabgrass specific product.

Answer 5

Apply a post emergent herbicide with MSMA, and spray weeds twice a week. your grass might turn yellow around weed but will recover. Make sure to apply a "Scott's with halts" fertilizer in early spring to stop the seed from crabgrass from germinating. This usually takes a couple of years but it is worth it if you stay on top of it.

Answer 6

Crab grass will die in the winter freeze up,but if you don't pull it out it will re-seed itself as it matures at the end of the summer.Are you sure its crab grass? You can tell because it dies off before regular grass goes dormant.You can treat it with PRE-EMERGENCE in the spring.A good garden centre will carry different brand names.

Answer 7

Put down St. Augustine grass.....it wil choke out just about anything. It is almost a weed.

Answer 8

Weed be gone & Scott’s fertilizer

Answer 9

The only way I have found it just to dig it out.

Answer 10

PUT SALT WHERE YOU THINK THE ROOT IS AND THEN POUR BOILING WATER ON THE TOP OF THE SALT------CRAB GRASS IS DEAD

AB