Thanks I'll try that.

Here's some pictures of some blades I took from the patch. I also discovered another larger patch in a totally different location.

You might need to zoom in to see the rust and damage.

I've got a fair amount of rust this year in NJ and never had it before. The prescription is a little nitrogen to help your grass grow out of it but I don't know if that is the best thing to do now in July. I'm pretty sure I have rust but the majority of it sticks to the blade like it is a permanent lesion, which I think it is. I was only able to get a little of the rust to come off on my fingers. I'm not sure what soap would do in my situation. Can you rub it off? Mine looks like this:

Yeah that’s what mine looks like too. I just put down turf builder last week so maybe that’ll clear it out.

Dan, Purdue recommends 0.2-0.5 lb/k N: rust

That isn't a lot. You could use Milorganite or a slow release synthetic and not push too much growth. As long as you water when needed (early so blades dry quickly after the sun comes up), I think it would be fine to fertilize a little bit.

I have some extra turf builder so maybe I’ll add it on these spots.

How much did you put down last week? More is not necessarily better. If you did 0.5 lb/k (or more) last week, that should suffice.

I put down 2.5 lb per 1000 square feet approximately.

If you put down Turfbuilder 32-0-4, you applied 0.8 lb/k of N (32% of 2.5). That's plenty. If yours had a different NPK, multiply 2.5 by whatever percentage of nitrogen it was.

@becky: I used Oceangro in early June but I don't really see much difference in the rust. It's a little hard to tell if it is better, worse or the same. I see you're saying it doesn't matter when you put nitrogen down since it is such a small amount.

I looked at my bottle of Serenade. Under turfgrass the two diseases listed for control are powdery mildew and rust. I'm using it to see if it will help with brown patch. I know you probably want to avoid fungicides. This is a strain of bacillus subtilis. It's meant to be reapplied throughout the time disease is likely. If you want to give it a try, this place has a good price now: Serenade

Thanks becky. Do you know what effect Serenade has on beneficial fungi including mychorrhizae? My only reason for not using fungicides was that they destroy part of the ecosystem we're trying to build with all the organics. At this point I'm considering to use fungicides on 1/2 my lawn for a year and see if I notice any differences.

Serenade does not affect the fungi. It's adding more of a bacteria that's in soil anyway. Did you watch that video on Serenade's mode of action? I'll look it up: Serenade

I get the impression that farmers and nurseries use it mainly because it makes the other fungicides they use more effective and resistance doesn't build up. In relation to turfgrass, I've read about it as a preventative rather an a curative. But if it lists rust on its label, maybe there is some curative effect. It should at least help prevent further outbreaks if you keep using it. The video mentioned 10 days of coverage and I've heard to apply it every couple of weeks. As for my brown patch, I have some but it's not as bad as some years and grass is growing back. I think, for me, it's just helping make a stronger grass plant. I refuse to use fungicides. If the grass dies, I'll replant in the fall. J4C11 says dead grass isn't helping the mycorrhizae. But not all the grass is dying from brown patch and I want the mycorrhizae around to help the grass that does survive. If you do use synthetic fungicide, look for one that is less harmful to mycorrhizae (I have a post on this, maybe on the other forum or I may have put it on this one too).

Serenade is worth a try. I've used it on powdery mildew and it works great. I've sprayed it on an asian pear tree that was sickly for several years with spots on it's leaves--it miraculously cleared the spots and the tree then flourished. It probably isn't effective on hardcore lawn diseases but I'd definitely try it on something as mild as rust.

I should clarify. Serenade does not affect the underground fungi. We are hoping that it will indeed affect the fungi on the leaves.

beckyinrichmond I suggest when youh replant grass patches wiped out by fungus you also dig out the dirt about 4 inches and replace it with a mix of top soil and compost, then plant the new grass on top of that. That's what I did last fall when I got brown patch from stupidly watering in the evening and it's worked great. No more brown spot, but I do have rust, haha.

Interesting idea: get rid of the soil harboring the sclerotia. However I have spots here, spots there and it would be a lot of digging. If I were to do that, I would use just topsoil, not a mix of topsoil and compost. The compost will decompose in the coming years, leaving a depression. I do have grass growing back in the affected areas so if I were to start digging, I would be digging up live grass too. So a general overseeding should suffice. Are you going to try the Serenade?

I just put compost on top, beneath the grass seed, and sprinkled on top of the grass seed because it provides so many nutrients and locks in water for the new seed. I will use serenade if the food and watering doesn’t solve the issue.

UPDATE: the places with the rust have now gone completely brown. The grass is wilted and appears to be dead, but the actual rust “powder” is gone. It looks like a brown disease now. I’ve attached some photos. Please help me figure out what the heck is going on.

If you think it may be something else, use this tool to try to identify it: turfgrass disease id. Then after you identify the disease, this has information on the various diseases: diseases

Rust can cause the whole leaf to die. But if the crown and root are okay, it should be able to grow new leaves. It is grass under stress, though, and it is vulnerable. Looks like you still have green leaves mixed in. The whole area isn't dead.