I used crab grass killer long ago, results were less than mixed. Maybe they've made improvements?

Another trick is to cut the grass high so the taller varieties squeeze out the crabgrass.

Or just pull the seeds when they appear to cut down on next year.

Neither is an option for me, but tyvm.

salt, or boiling water.

exacerbates the problem. I used to use an old pair of high heels. Some use golf shoes, but the cleats do not go deeply enough. They work fine, however, if one is just sowing clover!

a spade if it is bigger. I try to get under it with a shovel and then pull it out.

repeat

Describe in feet. Is it in the middle of the grass or is it a separate section? Depending on size, I may have a very easy solution for you.

It's a real PITA because it grows ridiculously quickly.

TYIA!

however, let me think on it plus I will ask some other gardeners. I'll post back after I have a chance to do this.

An idea came to me. However, I need to do a little research to tell you the best way to take care of it.
BB after I do this research.

First, I checked the organic suppliers and they have non-toxic weedkillers, but I doubt that it will kill crabgrass. To check for yourself, go to Bonide and put in weed killer crabgrass. You'll get entries, but I note none of them specifically say they'll kill crabgrass. I tried this with other organic garden supply companies and found the same.

What you could do if you don't mind how it looks for about a year is solarize it. Some people would use plastic for this, but I wouldn't. I would get as many large sheets of cardboard as I could and lay it over the crabgrass. Then I'd buy straw bales and put it over the cardboard. At $13 a bale, your first round will be less than $100 to cover the space you're looking to cover. I'd be sure the straw is at least 10" thick.

Your second round will come just as you go into winter.

Like I said, you'll have to tolerate this patch for a year to kill all that crabgrass. OTOH, it will enrich your soil as it breaks down and when you re-sow the grass, it should be pretty nice.

Next spring, before seeding directly, I'd clear out the straw and put plastic over this section and let the sunlight kill any seeds that are left. You don't want to rake the ground, but it's ok to rake if cardboard is underneath. Then pull up the cardboard after you've raked the straw raked into one pile.

If you go this route, I'll give you tips on where to get large pieces of cardboard.

I have a feeling you're not going to want to do this, but it's the only thing I can think of that keeps dangerous pesticides away. Even high test vinegar, should you put it on that stretch, will ruin growing anything there for the future. The pesticides you already know about--like killing your ladybugs and parasitic wasps.

I wouldn't mind the cardboard & hay, but this redneck town would likely complain.

I appreciate all the time & effort you put into this, but I can't do this.

I have another idea but I have to locate the product.

About 6" in the 2 days since landscaper was here mowing. I'm just not willing to spend my money this way & might need to resort to a chemical that will kill it but not the groundcover & violets.

the lawn forum at Reddit that there's nothing that "really" kills it. It always comes back, no matter what you use. You can use the most dastardly poison out there but it still won't kill it.

I have some better ideas. Just give me a little time to check some stuff out.

Ok. Tyvm!

did some practical experimentation. I plan on doing more. As of yet, I haven't finished the research on my options.

First, we have a big crabgrass problem at one of my school gardens. It is so bad that during the heat wave we had here in Jersey about 10 days ago, the crabgrass took over some of the beds. My solution is what I described to you above, which is effective with not much work plus it's inexpensive. However, this solution only works in some instances, as you have told me your town would give you some grief over it.

Similarly, I have one bed which my science students planted that has their plants in it, interspersed with crabgrass that has tenaciously taken over (I might get a pic), and I cannot use any means other than pulling it. I did that and let me tell you, it was tough. It was so difficult that I had to put the sprinkler on it to loosen the roots. That helped, but it still wasn't a cream puff job.

At the same time I was doing this, one of the male gardeners stopped to observe and said watch me.
He went to an open bed that had been taken over by crabgrass, got the mattock out of the shed, and in about six swings had the entire ground broken up to where the crabgrass could be picked up an thrown in a bin for disposal. I was impressed!!

What this says to me is that if you want a lasting solution, you could divide this job up and do half one day, have the guy clean it by raking, making sure nothing is left in the ground, and then proceed with lawn seed. If it works, then move on to the second half. You will have to baby it for a time, meaning water it, etc., but in the long run, it will behave like the other grass and you won't have this aggressive patch growing.

One thing for sure, I doubt people like you and me could swing the mattock that way, but some guy could.

More tomorrow, when I get the research on my other solution. I am having a blast with this second solution, but I know you won't like it.

Ty so much for all your diligent research & taking time to share it.

I had to look up what a mattlock is. Lol. I know it as a pick axe & I'm pretty sure I bought one with the house. The prev owner had lots of gardening tools I'd purchased.

Now to get gs to dig that crab grass out!

Yes, the town would have fits if I covered the crab grass & left it that way to kill it off.

Ty so very much!

I was remembering from the info I got from Redditors who used pesticides is that crabgrass doesn't have a solution once it's established (other than pulling it, which a lot of people actually do). They said the pesticide looked like it had killed it, but over time it came back. I think they were talking about within a year.

They said the way crabgrass is supposed to be attacked is through a crabgrass emergent, which you put on in the beginning of the season to prevent it from forming (or emerging). I think these emergents are dangerous, too, but I'm not sure. Will have to look it up.

Ty so very much again!

Thanks, though.

periodically to get what I missed.
Came out after rain and watering that loosened the soil.
A project, yes. Kept after the strays. A chore that had to be done if I wanted an appealing lawn.