Some combination of last summer heat plus this winter freeze screwed over 2/3 of my back yard st Augustine lawn. I believe I have every possible weed growing … grassy stuff, clover looking stuff (dollar weed maybe), you name it, I think I have it. I don’t like using chemicals, but last week, I was at the local Lowes and bought a bottle of Ortho weed killer that’s supposed to kill a billion different weeds. You attach to your hose and you spray it around. the result is comical. The grassy looking stuff shrugged it off. The clover looking stuff didn’t care either. Everything else (broadleaf?) died, leaving behind sad yellow weedy corpses. So my lawn looks 1/3 st Augustine, 1/3 grassy and clover looking weed, 1/3 yellow dead weed. CF, where do I go from here? I don’t care about my lawn enough to pay a crew to put in new sod. I’m half wondering if I just let warm weather come and st Augustine will resurrect itself.
Sounds like my backyard - at our previous house I was borderline obsessed and had everything looking great. Moved 1.5 years ago and inherited a salad bar of a backyard that doesn't drain well. To get it looking nice and uniform you need to kill the weeds and probably re-sod at least the really bare areas. You probably also have a lot of wild bermuda in there like me which is hard to kill without going nuclear with roundUp. But, give it another couple of months if you want and see how much of the St Aug starts coming back -- it's all just now coming out of dormancy. I'm living with a weird St Aug/Bermuda mix and trying to control the weeds for now. If it were the front yard it would be a different story and I'd be more inclined to re-sod. The hose-end sprayer stuff usually takes multiple applications to hurt the tougher weeds. CelsiusWG is supposed to be stronger so may have better results, I haven't tried it yet but may soon. BTW those yellow corpses will disappear over time too
Grassy stuff sounds like bermuda. You can't kill Bermuda with weed killers and St Augustine won't win against it. you'll have to kill it, remove it, and re-sod if you want St Augustine. If you want to embrace the bermuda, leave it and mow it low every 3-4 days. 2" or lower, using a sharp blade.
Celsius is legit. Bonide weed beater works well too. Is you have your own spray mixer, use Turbo Spreader Sticker - it helps the chemical stick to the plant. They say use dish soap in a pinch but Turbo is cheap and works better. Nuke the yard again, and then use a pre-emergent like Barricade. It won’t stop existing weeds but prevents future weeds. Works great. After the initial round of treatments you’ll need to reevaluate what’s left then try to spot treat those by identifying the type of weed, which is important for selecting the right chemical. like Gabe mentioned - if it is Bermuda, it won’t be stopped by weed killers. Atrazine slows it down a little but eradicating Bermuda is a whole different kind of endeavor. St.Augustine will bounce back fast with a little TLC. Fertilize, Top dress troubled areas with compost and even aerate if you want to do all the things.
I'd stop buying the stuff from Lowe's and go to a legit garden center and ask them what to do. From what I have been told, weeds grow when your grass isn't thick enough to keep it out, so you need to make your soil healthy and your grass healthy, while killing the weeds. Killing weeds alone isn't enough if the other two aren't done. I've been reading the garden line stuff (formerly Randy Lemmon) and trying to pick up what they recommend, because my lawn is in the same situation. We'll see how it goes. If you haven't already, try putting out a pre-emergent so that you can get new weeds to stop growing (it won't kill your current weeds though).
The original Cornelius Nursery on Dairy Ashford was always the go-to for my folks. I think they have a couple of others now in Houston.
Celcius for pretty much everything except sedge weeds. Prodiamine asap for Crab grass this summer and do it again before winter for cool weather weeds as soon as you get those grassy weeds gone, drop down some fertilizer to get the grass going. If celcius is too expensive you can get some 2,4D. https://www.homedepot.com/p/Compare-N-Save-32-oz-2-4-D-Broadleaf-Weed-Control-75311/203112354 https://www.tractorsupply.com/tsc/product/gordons-amine-400-2-4-d-weed-killer-1-gal-4201014 and accept it won't kill as many things as celcius does or paint on glyphosate on what 2,4d doesn;t kill (like literally with a brush which sucks) Per application, the pro stuff is way cheaper than anything available in a regular store. One bottle of celcius will last you, your family and friends, years.
Well, a week later, I’ve decided I don’t mind the Bermuda at all, and the st Augustine is starting to grow. The broadleaf stuff has been zapped, and maybe I’ll drop down some weed and feed, unless Cf tells me that is hot garbage too.
I feel like I'm talking to myself in the mirror. I don't want to contribute to fertilizer run-off and red tide. I usually just keep whatever it is mowed and most of the weeds die in the heat. But, the grass goes yellow cause they can't get enough water and I'm finicky with the water due to bill so f off grass. If you can't be smoked, then f off.
Yup. Individual and specialized application is the way to go. Fertilize and spot treat weeds as needed. Plus those weed and weeds can have a negative impact to nearby trees