Help with Lawn Problem - Fungus?

Hi Everyone,

I'm about pulling my hair out on this lawn issue. My backyard was new sod last year (Detroit Metro Area) and had a troubled start where it was installed in the hottest time of the summer and didn't get watered for many hours after install, no thanks to my landscaper. It literally look over a month and a half to take root. Regardless, by last fall it was looking good.

This spring, I noticed it's very green and growing well (I mow it almost every 3-4 days), but looks very thin when looking straight down on it. At an angle, it looks thick and lush. It's been a very wet spring and there is little grading to this part of the lawn. The house is south facing, but this part of the backyard gets sun almost all day (~10AM to sunset). I also notice a large amount of "dead" plant material under the green blades, but doesn't resemble thatch. I am not sure of the grass species.

I aerated this spring (I know, not the best idea), attempted to overseed, fertilized as usual, and am in the process of a course of fungicide as I notice leaf spot. Also hit it with GrubEx as insurance against those pests. Soil test show nothing abnormal (ph 6.7, N/P/K "normal"). The useless landscaper who installed it thinks it looks fine. There are more grass blades going every which way, instead of straight up like the other areas of the lawn (not recently sodded).

I keep a super-sharp mower blade (sharpen monthly) and haven't watered the lawn yet this year, just lots of rain and now humidity.

I'm stumped, unless a nice fungus has taken over. Any ideas?

Thanks for any help!

 

What type of grass do you have?

You ask if a fungus has already taken over your lawn but you said you are apply fungicide already and on the whole the lawn does not look bad. What fungicide are you applying?

Some amount of dead grass will be visible in almost any lawn. If you have to pull the lush green grass back to see dead brown leaves below than I generally don't consider it a problem. Even in your closeup it doesn't look like rampant leaf spot.

Generally most lawn fungi are made worse by too much water either from irrigation or Mother Nature. Fertilizing during periods of excessive water can cause further problems by forcing the grass to grow quickly and the new, soft growth is more susceptible to fungus.

 

I'm not sure of the grass type, but most lawns out here are a blend of KBG, Perennial Rye, and Fescue.

I noticed some leaf spot almost a month ago, and applied the Scotts fungus control product (thiophanate-methyl), with no real improvement. I hit it with Spectracide Immunox yesterday (myclobutanil). I'm trying to determine if I should pull out the big guns of fungicide (Heritage, etc.), or wait it out for the hot and dryer summer weather. Or is it possible I should look at something else? I've never dealt with leaf spot and thin grass like this.

Weather has been horrific this past week for fungal growth - 80's and humid during the day and storming virtually every evening, so the lawn is nice and wet all the time.

Thanks.