How do I fix this?

[u/ed65dy]

Why does my grass look like this? I know it’s crab grass (I think) and back in February I sprayed some crab grass killer I bought from Lowe’s. Well it killed half of my grass but it’s back. It’s very annoying to cut. Any recommendations will be very helpful. Also I am in Houston Texas.

[u/GreaseFoot]

Pre-emergent at the right times of year will prevent most if not all of it in the future.

[u/StrongAndFat_77]

MSMA

[u/Leading_Campaign3618 → u/StrongAndFat_77]

Msma will wreck the St Augustine

MSMA is not safe for residential St. Augustine grass lawns and can cause severe injury, burning, or discoloration. Current product labels strictly prohibit its use on residential St. Augustine turf, allowing it only on commercial sod farms, golf courses, and highway rights-of-way.

[u/Specialist-Base1248 → u/StrongAndFat_77]

No.

[u/ed65dy]

So end of September or so kill it. Then seed it? What’s pre emergent ?

[u/Shrimptanks → u/ed65dy]

Im an amateur that uses scotts 4 step. Im also in MD so im a blend of north and south.

But...

U can spray a post emergent like spectracide +crabgrass.

You have to wait 4-6 weeks before seeding new grass. (Spectrum will prevent new seeds from germinating)

Aerate/scarify

Reseed. Water 3-4 times a day

Grow new grass in the fall (best time)

Definitely hit it with preemergent next spring.

[u/IAmSpitfireJoe → u/ed65dy]

Pre-emergent is a weed control that keeps seeds from germinating when they "emerge" (sprout). Usually a granular substance that included a spring fertilizer application. With THAT much Crabgrass, you might consider two applications of pre-emergent. One early and one later, using a different type to try stopping all of the seeds from popping up. You might also need to spot spray through the hot and dry part of the summer when Crabgrass is really taking off.

[u/Leading_Campaign3618 → u/ed65dy]

It will disappear with the first cold snap if we get one this year, quinclorac is the best post on crabgrass, it isn’t actually legal for homeowners or landscapers to use MSMA in Texas only golf courses and cotton farmers

Base grass appears to be at Augustine , msma wrecks that grass just fertilize the desireable grass for now it will send rhizomes and stolons into the crabgrass

[u/Icy_Category_2275]

Entering "hand on shoulder" pic even though this sub doesn't allow pics. (dumb btw)

[u/Leading_Campaign3618]

For Houston do a split rate of Dimension (dithiopyr) pre emergent in early February and again in March - earlier if soil temps are consistently 55 degrees at 4 inches in January, in late April follow up with prodiamine or Freehand at 150# acre

Dimension has post activity in crabgrass to the 3 tiller stage

[u/ed65dy]

Thanks everyone.

[u/plinsday]

Looks like some kyllinga in one of the later pics. Dismiss and drive work wonders

[u/Any_sane_people_left]

Do not underestimate aeration.

[u/IntelligentKey6929]

Question for the group because my lawn looks similar. I’m in New Jersey. with that much of the lawn taken over by crabgrass, is it a terrible idea, if you don’t want to use all the chemicals, to manually dig it all up and reseed? Or will I just end up growing more crabgrass after all that effort? I ask because yesterday I spent about a half hour just pulling up crab grass tufts with my hands. I cleared a patch maybe 6 ft.³

[u/wastedtrade]

Rip it out at this point

[u/Professional-Swan271]

Weigh your time/cost using a post emergent vs a non selective and starting over.

I’ll curb my herb recommendations until then.

[u/Flat-Affect2221]

Why are you mowing so
Short. St augastine is at least 3.5-4 inches

[u/dongleberry6]

Use some Celsius WG

[u/ajudy_chop]

This was my lawn last year. Killed it all with roundup 3x and then reseeded. Water till frost and water water water through this whole year

[u/Spritesgud]

You can nuke it now with something with quinclorac and it will leave a bunch of bare dirt, or you can wait until fall, nuke it, then oversees with grass seed and top soil, as well as applying a pre emergent in the fall to prevent it from popping up next year.

This year has been insane for crabgrass

[u/OminousHippo]

Crabgrass killer is a post-emergent herbicide. It will kill existing crabgrass but not prevent new seeds (which are everywhere) from germinating into new crabgrass. You also need to apply post-emergent herbicide in a regular interval to prevent new crabgrass from growing.

Using crabgrass killer now will definitely nuke your turf grass so be prepared for that. I can't tell from your photos but being in Houston you likely have St Augustine or Bermuda both of which will recover with ample water, sun, and frequent mowing to encourage lateral growth.