Moisture stress and turf disease can lead to brown turf

Tue, 07/01/2008 - 12:38pm
By: The Citizen

By Brian Arnold
Special to The Citizen

Faced with moisture stressed lawns with areas that have “browned out” and declined over the past several weeks, many homeowners are struggling to determine what they can do to help their lawns recover.

The easing of outdoor water use rules by the State EPD has aided in efforts to recover from moisture stress, but in several instances the problem with decline has been compounded by the presence of disease.

In regards to moisture stress, infrequent and deep watering, which encourages deep root growth and minimizes risk of disease, is ordinarily advocated over frequent and shallow watering. However, increasing frequency may be warranted for the time being, so as to help turf recover from drought related decline. Of coarse one must stick to the “legal days” and upon recovery, frequency should again be reduced to as infrequent as once per week, provided that doing so doesn’t result in a return of moisture stress.

Increasing watering frequency may aid in turf grass recovery, but on occasion doing so may make matters worse.

Complicating matters in regards to supplying additional water and helping lawns recover from moisture stress, is the fact that turf grass diseases have caused significant damage on some of the lawns in question, and providing more frequent irrigation may proliferate respective disease.

There truly is a myriad of turf grass diseases, some more common than others, and some that until recently, were not well understood. As it is with such maladies that attack us, there is still much that needs to be studied and better understood.

Turf grass diseases, which require presence of free standing moisture in order to proliferate, have seemingly been successful at attacking some lawns that have been weakened by the drought and subsequent water restrictions. The recent wave of disease has affected turf grasses of all types, but has seemingly been especially troublesome for zoysia, centipede and St. Augustine lawns.

In several cases, it is probable that disease outbreak coincided with resumption of overhead irrigation; hence, a supply of free standing water needed for disease development. However, morning dew alone supplies adequate moisture for the development of disease, and can be attributed to outbreaks on lawns that haven’t been irrigated.

In many of the instances in which turf decline is at least partially the result of disease, the culprit disease may have already completed its damage and therefore the application of a fungicide may not provide benefit. Still, being aware of possible disease pressures will help in managing turf quality and preventing future outbreaks.

If disease is suspected, proper diagnosis is the first step in its control, and the aid of an expert may prove useful.

If you have a professional lawn care provider, let the provider know if you notice an abnormality and suspect that it may be disease. It may be weeks before they are scheduled to visit the property again, and a lot of damage can occur before then. And please, don’t get angry because when he was on your lawn three weeks ago, he didn’t know your lawn would have disease today.

If you don’t have a professional lawn care company that you can rely on for respective diagnosis, contact the University of Georgia Cooperative Extension Service for help. They will advise you regarding diagnosis and if necessary, instruct in the proper procedure for collecting a “sample” to be brought in for further analyses. In the event of disease is verified, the Extension Service will provide advice regarding control. It’s a great service.
Regardless of if disease was involved with decline that your lawn may have suffered, proper maintenance practices are critical in regards to turf recovery.

We have used core aeration to help several lawns recover, with very good results.
Frequent mowing is critical too, even if turf isn’t growing much. If you believe that cutting higher will benefit, then do so. But simply raise cut height of mower and maintain a mowing schedule of at least once per week.

If disease is present, bag and remove infected clippings to minimize risk of its spread.
Getting rid of thatch, which increases likelihood of disease by trapping moisture at interface of root and blade, and encourages undesirable shallow root growth, is helpful as well. Core aeration will aid in this endeavor but de-thatch equipment can be rented as well.
Proper nutrition management is critical for turf recovery and disease management as well. Unfortunately, this topic, along with the others, is too involved to address at any length.

Needless to say, proper watering is a big help too.

Given time and effort, a lawn that looks like a lost cause can rebound to former days of glory.
Brian Arnold, Horticulturist & Certified Arborist, is Manager of Tree, Shrub and Turf Care at Natures Landscape Services, Inc.
His email address is

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