Yellow/Brown Spots in yard

[WolfAK]

Hi, new poster here. I apologize in advance if this post is to long. Hope someone might have some ideas. Live in Eagle River Alaska just outside of Anchorage.

Established lawn been in at least 10 years. I purchased house middle of last summer so this is my first entire season with it.

Lawn has been doing beautifully. Nice deep green, consistent color pretty and thick. Suddenly in last week yellow/brown spots have begun to appear randomly in the yard. The blades of the grass where the spots are appear completely dead and brown for the top half of the length and green below that. Not sure if the dead portion is traveling deeper down the blades.

I have not tested soil yet.

I did apply lime to the lawn last fall and once in May.

We had a record hot June with no rain but I did water the lawn every other day for a few hours. Actually had some mushrooms pop up during the "drought."

Couple things that have occurred last few weeks. I fertilized the lawn with Scott's Green Max with Iron. My possibly misguided intention was to try to deepen the green color of the lawn.

I usually keep the lawn cut at about the 3" setting on my Honda Lawn Mower. We have now gone other direction and have had a very wet July. I had not been able to cut the grass every 3-4 days like I normally do and the grass got very long. (I normally do not catch the clippings)

The sun came out for a couple hours and I decided to jump on this opportunity to mow. For some reason I thought it might be a good idea to cut it a little shorter so I set my mower to 2.5" ( I have no excuse I know really bad idea) and bagged those clippings.


This is when I first noticed the yellow spots in the lawn. They appear to be getting worse. I love working in my yard but I am afraid I have hurt this beautiful lawn.

[imafan26]

Sometimes if the lawn gets too much fertilizer and water, it puts on lush tender green growth and makes it very tasty/tempting for army worms and cutworms. The moths lay the eggs in the lawn and the caterpillars eat away at the roots and tender shoots causing brown spots.

These same caterpillars in the garden are the cutworms that chop down young vegetable seedlings.

https://extension.usu.edu/files/publicat ... turf07.pdf

[WolfAK]

Thanks so much for taking the time to reply. I was thinking it might be some sort of pests as well. Will look at that more closely. Someone else suggested it may be a fungus evidently I have been loving the lawn to much by watering way to frequently. Will look at that as well.