Lawn fungus

   / Lawn fungus #1  


Elite Member
Mar 27, 2000
Eastern Virginia
EarthForce EF-5 mini-TLB (2001)
Does anyone have any suggestions on how to deal with lawn fungus? We put sod down this spring and it already has large round brown spots that must be fungus in it. We've treated it with a fungicide twice at 10-day intervals and it keeps getting worse. Is it possible that the stuff is working but it takes a while for it to show? Or is there something else I should consider? My wife is really bummed. She was looking forward to getting sod for a long time, and now it looks like a lot of it is dying.

   / Lawn fungus #2  
Mark, you say you've used a fungicide, but did you take any samples to a nursery, or similar business, to ask them if that was the problem. I doubt that I could help you since we're in such different climates and soils, but the only time I ever had a fungus problem, it looked like a blue/grey mold. Brown spots usually meant grubs (except when I failed to water or spilled a little Round-Up).

   / Lawn fungus #3  
If you have June bugs in your area then you have grub worms. About 3/8 inch diameter white and an inch and half long. Here in Texas they eat the roots. A good application of Diazon is pretty hard on them. Now that you are getting Texas weather up North, you may be getting Texas bugs (and worms) too. Pull up some of the dead sod and see if it has roots or if they have been eaten in two.
   / Lawn fungus #4  
Mark, I have Saint Augustine here in Bama and recently had a couple of place that were brown and dying..The odd thing is that it was almost an exact circle...Turned out as WEN says to be some type of grub....I forget what I used to get rid if them but it took a while before the grass recoverd and one place I had to cut up and replace the dead area..(about 2' in diameter)..I'm with Bird on the fungas I've seen blue green and even one that looks like soap was left to dry (all white and spotty)usually get the soapy type on my Crate Murttals in the spring.The last time I had fungas in my back yard I was time for a dethatching..The odd thing is the yard is cutt with mulching blades and a bagger...You would think dethatching would not be necassary...O'well if it is a fungas I 'd like to know for future reference..Good luck.

Lil' Paul

Laziness is the Father of invention.../w3tcompact/icons/laugh.gif
   / Lawn fungus #5  
Take this as impression rather than expertise. I think the fact that it's new sod would almost certainly eliminate some types of fungus as candidates, and those re the types would be difficult to treat with a fungicide. We had a type of fungus at a place in Denver that appeared as somewhat darker green circles that expended into rings, and the grass in the centre would turn brown. The rings would send up mushrooms sometimes.

A number of fungicides wouldn't touch the stuff. We got a thing that went on a garden hose that poked holes in the sod and injected water below sod level. The combination of the injector and a fungicide cured the fungus.

I remember a warning years ago here in Ontario: 'warning in the Niagara Peninsula. Hairy cinch bug infestations coming from New York State (Guess they didn't mean tourists). From the description, cinch bugs really chew up lawn fast and produce the results you describe. You might try digging up some sod and dirt at the border of a brown spot (if it's bugs, they'd have eaten everything in the centre and wouldn't be there any more). Run the soil through a fine screen and see if you find critters.

I forget what pesticide was recommended for cinch bugs, but I think most of them are pretty wide spectrum agents. For people who don't like to use pesticides, biological agent suppliers sell things like nematodes that control a variety of pests. Of course, skunks do a good job of controlling grubs, but that cure may have a few drawbacks.
   / Lawn fungus #6  

Did you try taking a sample back to where you bought it, or calling them to ask if they know what it is?


We boys and our toys!
   / Lawn fungus #7  
What sort of grass do you have? Zoysia will get a fungus called brown spot or dollar spot (since it looks like lots of small round brown spots). I've seen this occur if the grass gets too long and too wet. The solution is to keep it mowed nice and short - a reel mower is best - and spray on some fungicide. I use Funginex, but there are several choices that any good lawn and garden shop can recommend.

I think grass types and various diseases vary a lot with location, and I'll bet a lawn and garden shop can diagnose it and sell you a cheap cure almost instantly.
   / Lawn fungus
  • Thread Starter
Thanks, guys, you've given me some things to think about. I had the guy we got it from look at it, and he said it looked like a fungus, but we pulled up some of it and checked for grubs, but didn't see any. So he recommended I apply a fungicide, which I did, but I don't see any results. I'm just not sure how long it should take, though.

   / Lawn fungus
  • Thread Starter
Sorry, I forgot to say what kind of grass it is - Kentucky bluegrass.

   / Lawn fungus #10  
Mark - take a look at your watering habits. The last time I put in a new lawn I had trouble keeping up with the watering so I was running the sprinkler anytime I was at home. The areas where I was watering late in the evening were getting mold and fungus problems because they were staying wet for so long. Once I started watering only in the morning so the grass dried the problem went away.

I was growing KY-31 Fescue.