I just bought a house and now the whole lawn has crabgrass popping up everywhere and it is thick. Is there anything I can do? I know pre-emerge application is the best. But I was not in the home at that time.
Treat it for the problem grass, next spring.
Yep, hit it early with a pre-emergent next spring. It will not be a silver bullet to kill 100% of it as you described a whole lot. Remember, it’s the seeds the pre-emergent is killing and not the plant. I’ve always error on the side of too early rather than too late on the application.
With that said, I’ve found that Ortho Weed B Gone Maxx is effective at killing plants in small areas.
And save your money for next spring cuz you’re going to need it.
Until about 2 years ago, I don’t recall it being so expensive. Seems like the price tripled in a year.
I get the granular preventer and place it in the spring.
I don’t do the whole yard either since my lawn is large only the part I can see/use the most.
Treat it for the problem grass, next spring.
X2……….Crabgrass seeds germinate when the soil temp reaches 80.
Herbicide containing Quinclorac will kill it. Can get it off of Amazon. Make sure you get some Methylated Seed Oil (MSO) to mix with it or it will not work. I agree it is cheaper and easier to control it with a pre-emerge in the spring, but this will kill it as long as it is actively growing. Won’t work as well if you are in a dry weather pattern like we are here in NW Iowa.
Last spring I found some site that listed the right date given prevailing conditions for pre-emergent.-timing is important, stuff is supposed to do better as you apply year to year. Maybe someone knows the name of the site.
There are post-emergent sprays that can kill the live plants, but multiple treatments are usually required. Follow directions carefully or other grasses will be harmed.
As others have said, best treatment is in the spring by applying pre-emergent crabgrass killer, usually as part of a “weed and feed” fertilizer.
Grouse
It’s been said that crabgrass is holding Minnesota together.
For pre-emerge application the rule of thumb is to apply the herbicide when the lilac trees start blooming. Not sure where that rule came from but it works! Also, if you are doing the pre that is part of a dry fertilizer try to do it right before a rain or water the lawn right after even if it doesn’t need it.
I guess what I am looking for at this point is the best post-emergent spray that can kill the live plant. So far I see two suggestions: Ortho Weed B Gone Maxx and Herbicide containing Quinclorac with some Methylated Seed Oil (MSO). I know the treatment will not be cheap and I have 3 dogs that use this area. Does anyone have any other suggestions on products and application method that is known to work? I am mostly concern about the dogs. I have done some google searches, but most of the stuff I find is from the manufacture. I have a hard time taking the pushers word on it.
Safest bet is to hand-pull it, but if you have a lot, that will be torturous. Just stick it out till spring and deal with it pre-emergently.
Uh, mow it?
Spraying now will only lighten your pocket. Most of the crabgrass is already seeding and will be Browning up in a couple weeks.
Rule of thumb for quinclorac is to spray before the plant has “branched” three times. After that the plant is too mature and unethical doses would need to be applied.
Load up on Dimension preemergent and start over in the spring.
FYI…preemergent doesn’t kill seeds, it stops germination. Crabgrass seeds can lay dormant for upto 5 years.
Best practice is preemergent in spring and a dose of quinclorac end of June, early July. A few years of this practice and you should be seed free.
Thank you everyone for the information and help. Looks like I am up for a long battle.
I just bought a house and now the whole lawn has crabgrass popping up everywhere and it is thick. Is there anything I can do? I know pre-emerge application is the best. But I was not in the home at that time.
Are you sure it is crabgrass? There is a wide blade fescue that a lot of people call grabgrass. Grab grass will turn brown at the first good frost and the fescue will stay green. If it is fescue you will need to use regular Roundup and reseed after 2 weeks. If you can find out if it is fescue now I would treat it now and plant grass seed Sept. 1st and get the grass started now. Come spring it will take off great.
The crabgrass goes dormant in the Winter and pre-emergent simply prevents it from waking up. I used it every Spring ay my old house and I never saw it reappear all Summer long.
Ah heck, Give it a good old dousing of “2-4D” backed with a chaser clean of “Round-Up”. 
There ain’t nott’in better to clear the throat , I mean the lawns weeds, than a great chaser! 
Search YouTube for a channel called “The Lawn Care Nut”. He’s a former manager of TruGreen and knows his chit. He did an episode on crabgrass and explains everything you need to know.
That was a great video. Thank you. Looks like I need to pick up some Drive XLR8 for next year.
I just bought a house and now the whole lawn has crabgrass popping up everywhere and it is thick. Is there anything I can do? I know pre-emerge application is the best. But I was not in the home at that time.
I have had it for years.
Pre-emergent has not always helped, this year its bad.
Recently I bought and treated Lawn with “ORTHO Weed-B-Gon & Crab Grass Killer”.
Yes, It worked, massive amount of DEAD Crab Grass. I’ll give it one more treatment, then Seed & Water in Early September and then make sure I time Pre-Emergent Weed-n-Feed next spring.
Yes, I over-spray across the property lines to avoid neighbor’s poor habits from re-seeding my lawn with Crab-Grass.
FYI: Crab Grass Seeds may remain Dormant for 7-years. Thus, it is a Never Ending Battle.
From other’s, maintaining a Thick GRASS Lawn is one of best preventative measures. Do NOT Cut it too short, leaving 3″-4″ of length helps shade the ground, thus keeping it cooler and conserving moisture. When I Seed my backyard in September, I’ll do as I did on the front 5-years ago, using 5-Varieties of Seed at a Rate 4X recommended rate. Keep it moist/wet for until it germinates, then gradually cut back watering.
Best of Luck.
Seeing that all the snow has melted from my yard now and last year’s grab grass has dies leaving me with a mud pit. 
I think it is time to revisit this problem again.
I picked up some herbicide containing Quinclorac and some Methylated Seed Oil to hit the active growing stuff. I hand pulled out the larger plants.
I want to put down some pre-emergent granules. There has been some commits about waiting until the top soil reaches 80 or when the lilac trees start blooming. I am looking at different types of granular preventers. Are their some that work well without breaking the bank? Also what grass seed has worked well of you? I will be planting the grass seed in some shaded areas and some not, my soil is mostly clay. When is the best time to put the grass seed down?
If you use pre-emergent fertilizer it will stop both the crab grass seed AND your new grass seed from germinating.
I think the germinating temp is around 55 not 80. In Minnesota they recommend putting the pre-emergent down when the night time soil temp is stays above 50.
Do a search for a place called SiteOne. There’s one in Eagan. They sell commercial grade fertilizers and weed control. They also sell to the public.
I usually load up with Lesco 24/0/10 50lb bags with dimension pre-emergent for about $30 per bag.
The above poster is correct.You cannot seed until the preemergent has leached out of the soil. I would suggest getting ahold of the crabgrass and seeding this fall. Summer would work if you can keep up with the watering.
Best time to put grass seed down is September. 2nd best is April/May. THe problem you have for this spring is that you cannot apply a pre-emergent and grass seed at the same time. The grass won’t come up.
You could apply pre-emergent in the spring and then put seed down in the fall
I did a quick search and came up with this,I have this problem also….
https://www.greenviewfertilizer.com/articles/crabgrass-myths/
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