Will a Brown Patch Kill New Sod?

Brown Patch

• Brown patch commonly infects bluegrasses, fescues, bentgrasses and ryegrasses, according to the University of California. High humidity and warm weather cause brown patch fungal spores to germinate and spread over the lawn. If grass remains wet for an extended amount of time, it has a better chance of contracting brown patch. Some of the brown patches symptoms match unhealthy grass symptoms, so it is important for gardeners to correctly diagnose signs of brown patch before using fungicide.

Symptoms of Brown Patch

• Brown patch causes grass to discolor in a doughnut shape. An outer ring will remain brown, while the center will produce green grass. When there is an increase in humidity, this ring can turn dark gray or purple. Dead grass within the ring eventually appears tan and brittle. This fungal disease is commonly misdiagnosed in sod. Sod that is less than a year old and installed over compacted soil can display similar symptoms. Gardeners can tell the difference between unhealthy sod and brown patch by checking their sod in the morning for white fungal webbing that appears at the edge of the brown rings.

Cultural Control

• Gardeners may reduce the damage from brown patch by irrigating in the dawn hours or early morning, according to the University of California. By preventing wet grass blades and cool overnight temperatures, you can prevent the fungal spores from spreading to the rest of the lawn. Furthermore, water your lawn deeply so that the first 4 to 6 inches of top soil is moist. Only water your lawn when rainwater hasn't provided enough water for your lawn.

Chemical Treatment

• When cultural practices do not stop the spread of brown patch, gardeners must use fungicides. Check the fungicide's label to ensure that it will treat brown patch. Apply the fungicide every 10 to 14 days, as suggested by gardening writer Walter Reeves. Avoid using the fungicide if you grass appears water stressed or temperatures exceed 90 degrees Fahrenheit. Continue to use the fungicide until you see healthy new growth appear in the sod.