The Q&A Archives: Black Spots

Question: I had patchy, stalkly grass with some yellowing. Was told by Home Depot that I had an insect problem. Bought the product they recommended; applied it, watered and waited 7 days and then reapplied turf builder. Now I have several

Answer: It sounds to me like the classic symptoms of a fungal disease called brown patch. Brown Patch kills a circular area of the grass up to 2 feet in diameter. The infected area will change color and develop a likeness to frog?s eyes, having a circular spot surrounded by a discolored ring of grass. The grass in these patches will probably be thin.

The problem causing the ring is a fungus that flourishes in the warm temperatures and especially with damp conditions caused by thatch. The excessive nitrogen fertilization and poor drainage encourages the disease.

If your lawn is infected with Brown Patch, apply a flowable sulfur fungicide to the infected areas every three to five days until the symptoms disappear. Make sure you remove any underlying thatch with a rake or dethatcher to avoid the problem from reoccurring. Also, avoid applying heavy doses of nitrogen fertilizers to your lawn and improve drainage if necessary.

You may want to dig a sample of the turf and take it to your local cooperative extension office for positive diagnosis and control suggestions. Contact Sacramento County Cooperative Extension, 4145 Branch Center Road Sacramento, CA 95827-3898. Phone: (916) 875-6913.

Best wishes with your lawn.

« Click to go to the homepage

» Ask a question of your own

Q&A Library Searching Tips

  • When singular and plural spellings differ, as in peony and peonies, try both.
  • Search terms are not case sensitive.

Today's site banner is by cocoajuno and is called "Here's looking at you."