If you try to kill the weeds in your lawn with a herbicide right now, you will experience a repeat of what happened two years ago. You can try to pull the weeds by hand, or just live with them in your lawn until cooler weather arrives. Also, unless you choose to use an organic product, fertilizing your lawn now is not recommended.

It is simply too hot right now for herbicides or synthetic fertilizers on cool-season grasses.

Thanks but there are too many weeds to pull by hand. It's too early in the season to have to live with them til the fall!

Wouldn't it be OK if I use Weed-B-Gone spot sprayer on each weed? People here on the forum seem to like that product. Would it still be too risky to do it that way?

Are you talking about crabgrass, or some other weed? I have had good success using Weed B Gon in the summer heat, but I'm a certified applicator. I am very careful about what, when, and where I use a pesticide on turfgrass in a heat stress environment.

A small amount of crabgrass, but a cornucopia of several other weeds. Sorry I can't be more specific but I don't know how to identify any of them.

If I were to try spot spraying, does it matter what time of day, and when should watering be (before, after, none)?

Yes, if you were to do spot treatment, timing is everything. Wait until the coolest day possible, and read and follow the label, etc. Apply it when air temp. is below the range on the label. Personally, I have always thought that heat after the spray has dried won't really effect the pesticide's affect on the grass. I could be wrong in this, though.

Pictures of your lawn may help some to identify weeds. Any guess on how hot it was when you applied the Weed-B-Gon Max and how hot it got? Weed-B-Gon isn't the strongest pesticide out there, but almost any pesticide can get the best of your lawn if not used according to the label. Are you sure you put down the correct rate evenly?

It got into the upper 90s last year for several days after I applied it. It looked like the areas that got the most herbicide got the most brown and totally died. Being a schlub I was thinking "more is better" and I probably went overboard.

Thanks for all the advice.

I have been a schlub before, I know what that feels like. It is always self-inflicted. Yes, temps in the upper 90's after a "more is better" application of Weed B Gon on cool-season turf will not only turn your turf into toast, it will turn you into a schlub. And more is better? Lol...how did that turn out for you? Been there, done that.

Anyway, I'm not advising this, but if you want to try it, spot spray the weeds with WBG at the label rate. If you get any on your grass, and you probably will, expect to see the same results from 2 years ago on any grass that gets hit with the herbicide. Maybe you'll get lucky with a timely shot of cooler weather. Do not water for 24 hours after the application if you want it to be fully effective. If possible, apply early in the morning.

Upper 90's is definitely hot. Some of those things just come by learning it the hard way. ;-).

I would recommend considering doing something like a 3/4 or even 1/2 of the recommended rate twice - about a month (or maybe less) apart. While it won't be quite as hard hitting on the weeds it will be easier for the turf.

I would wait until mid to end of august and use a hose end sprayer and maybe use Bayer or Spectricide weed killer.
I killed some of my lawn with weed-b-gone max. It acted like I was spraying roundup. This happened in early May!
I threw the rest of the bottle out.
You can renovate in early September.

Just my opinion but I've never had a lot of confidence in hose end sprayers. I would think that the rate the chemical is dispersed would at least partially depend on the water pressure. I've tried it with several different brand sprayers with very little luck. I have spot treated weeds with a pump tank sprayer for years with good luck. It's a lot of work if you have a lot of weeds but if you go after them at least once a week, you'll be surprised how quickly you'll cut them down. I'm down South with warm season grass so I don't seem to have problems with the heat when using WBG. Or maybe I'm just lucky.

I used WBG Max last year. It was the premixed stuff in the plastic tank. You pull the lever and get a 10-15 precise spray. I mainly did this for creeping charlie and it worked very well.

But it DID stress the lawn. I don't think it outright killed it, but it was certainly not kind. This year the lawn is filling in the areas where the creeping charlie was. So I'd say it worked pretty well.

But I only do it for spot sprays; I would never use it over the whole lawn. IMHO, it's best to get a lawn company to spray the whole yard if you have a widespread problem. I wouldn't use the hose sprayer either -- way too imprecise.

I agree. I wish there was better solutions then hose-end sprayers. My concern with them is the contamination of everything. With some products, it's not as big a deal, but all pesticides are still very dangerous.