Crescent moon shaped spots in my lawn

[Wellesy]

Mowing at the apartment building I manage last night, I noticed several areas that had a dead(?) spot shaped like a crescent moon. Is this a pest issue or fungus? How might I go about treating this?

Thanks for any help on this.

[MNmikew]

Perhaps someone was painting the door to their outhouse on the lawn?

[Powerstroke]

Difficult to diagnose without seeinf the actual spot, but it would be my first guess that it was a fungus or maybe a chemical burn.

Are the spots pretty consistant in size and shape? Something that comes to mind was when the mower forgot to replace his gas cap and the fuel sloshed on every turn. There were several half circle marks where the fuel burned the turf.

In order to check for fungus you would need a few blades of grass to look at to see if there are any spots or marking on the blades.

[sparcebag]

My first thought was ALIENS!

[Scott K]

I thought aliens leave full circles

[Wellesy]

Loose gas cap was my first thought but each spot is about 4 feet long end to end and they are on smooth, level ground where I don't make any turns with the mower.

I'll look at some of the grass when I get home tonight and let you know in the morning.

Aliens...

[Powerstroke]

What I would be looking for would be a spot or hourglass shape on the blade of the grass. The hourglass portion is width-wise on the blade.

The other obvious thing would be if you fertilized with a rotary spreader and that was where you made your turns with the spreader. During the turns its very common for the same amount of fert to come out, but it drops off instead of spinning of the drive wheel of the spreader is on the inside of your turn.

[Wellesy]

Powerstroke - I got home quite late night and did not look. Pending today's weather (stormy it looks to be) I will check some blades.

We have a fellow who sprays the lawn with fertilizer, no rotary spreader involved.

[Tim Ellis]

Wellesy, I think your issue is called fairy ring. Look it up and i bet it will match your situation. Good luck. Here is a link: http://plantclinic.cornell.edu/FactSheets/fairyring/fairyring.htm

[Shack]

If none of the above leed to anything, I had small half moon shapes show up from exhaust of old lawn mower. It burned oil and exhaust was directed twords ground and if I stopped and let idle for a minute or two in a spot, grass would be dead in a week. Also female dog urine casues dead grass area's.

[Wellesy]

Tim - That sure looks like what I have there. Guess we'll just make do for now. Thanks!

[Tim Ellis]

Wellesy, I think the best route i found is to try and even the color with adding fertilizer to the surrounding area to match the green. Also aerating the area can help "dry" out the soil in this area also. Good luck.