“Crop Circles” in Bermuda Grass

rawknee – posted 30 July 2010 15:14

We’ve been in our home (McKinney, TX) for almost 9 years and over the past 3 years or so we’ve begun to notice dead spots in various areas of our bermuda lawn. We’ve been calling them “crop circles” for lack of a better term. Unfortunately, they’ve been getting bigger and we’ve notice more of them each year. Hubby has attempted to resolve the issue with various tactics – up to and including digging the sod/soil from the affected areas and putting in new sod but the same spots end up dying back within a month or so.

We’ve been using a great lawn service for the past 7 months (weekly maintenance as well as pre-emergent and fertilizer treatments) in the hopes that they can help us keep the lawn as healthy as possible. 80% of our yard is beautiful – 20% is scattered with “crop circles” that range in size from a dinner plate to a truck tire.

They’ve recently done some analysis on the soil to see if the can figure out what’s going on with our dead spots. We’ve been told it’s not grubs, not a fungus, not the result of any weed killer/chemical damage, etc. Turns out the pH of our soil is 7.9 (too high) and they’re recommending a series of aeration/treatments to get the pH where it needs to be to support healthy turf. We likely wouldn’t see results for 12 months. (yuck) We’re willing to go this route if that’s what it takes, but I’d love to get a second opinion.

Thanks in advance for any help.

turfgrass – posted 30 July 2010 22:49

tough to say what your spots are w/o pics.

using ammonium sulfate as your source of nitrogen will certainly help lower your pH though.

rawknee – posted 02 August 2010 08:16

After doing a bunch of research on-line, I’m pretty sure we have Spring Dead Spot.

Anyone familiar with this and the appropriate way to treat/resolve?

Thanks!!

cgaengineer – posted 03 August 2010 09:06

Rubigan fungicide is labeled for use against SDS but I am wondering if you actually have SDS to begin with. Rubigan is very expensive and the treatment process starts on the spots before winter and through the winter. The smallest container of Rubigan is about $350-$400.

What do the roots look like on the affected spots? Are they black?

Do these spots show up in the same spot every season? Generally SDS spots are located in the same spots year after year, they also eventually fill in before the summer is over.

To me this does not match the symptoms you describe.

[This message has been edited by cgaengineer (edited 03 August 2010).]