Picture: Tom MacCubbin
Perhaps you can say the season has been just right. You love the warmish weather and the green lush looking lawns. You may be applying a little extra water and have given the turf an extra feeding. Well guess what? The brown patch, also called large patch, fungus loves it too.
Gardeners are waking up to an almost overnight yellowing of their lawns. Usually the symptoms start out a very light yellow color and over a few days turn orange to tan in circular to oblong patterns. Now take a close look and you might see a bit of green in the center of these areas. It is called the ‘donut effect’.
That yellowing look to many lawns is likely caused by the fungus that may not be properly named brown patch. Because, at first it is yellow. Maybe the name large patch is better as these areas can grow considerable in size. The disease is encouraged by the warmish weather and seems to affect mainly St. Augustine, zoysia and bermuda turf types. By the time you see this fungal activity the disease is well-established and done most of its damage.
Where does it come from you may ask? Well, it is a fungus that commonly lives in the soil. It is there all the time just waiting for the right conditions. Late fall, warmish winters and early spring are normally ideal for your lawn and this fungus too.
Applying a fungicide can help prevent the spread of the disease, to other turf areas of the landscape. It is not going to help with areas already in decline. Garden centers have a number of good fungicides labeled to help control this disease. Pest control companies also have an arsenal of newer products not yet on the home market that may give even better control. Some of these are available at do-it-yourself pest control stores.
When lawns are affected yearly by brown patch, an early November fungicide application is often recommended. This is normally following a month later by a second application and a third application in late winter.
The good news is this disease normally does not kill a lawn but does make it look bad until spring. Affected grass blades remain brown but the runners are usually green. The lawn then regrows new blades come spring when given normal care. Do keep the site moist but not overly wet during the winter and apply a fertilizer in spring.