Brown Patch Lawn Disease
Brown patch is a fungus that we run into every single summer. All summer long, the weather forecast seems to be, ‘hot, humid with a chance of rain’. Well, this constant ‘wet’ forecast is conducive for fungus to grow and and thrive in!
The most commonly grown and most tolerant year-round grass type in the Triad is tall fescue. It is fairly tolerant to drought, maintains a nice, green color and is fairly low maintenance. However, it is also very susceptible to fungus during wet weather. Brown patch is a common fungus that we see mostly in the months of June, July and August. Unfortunately, brown patch can also kill your lawn without proper prevention or if it is not taken care of as soon as it starts!
Brown patch is exactly as the name implies. It looks like circular, brown, tan or yellow patches ranging from 6” to several feet in diameter. You will notice brown patch when the humidity is high or when we have been having afternoon thunderstorms or days of wet weather. For this fungus to activate, the nights have to remain over 60 degrees and the grass needs to remain fairly wet. These conditions will cause the fungus to grow at a rapid rate.
A fungicide application should be applied to prevent spreading of the disease. Our preventative program provides multiple applications, every 21 to 28 days, while weather conditions favor the disease. Do not irrigate lawns in late afternoon or evening if possible. This extends the number of hours the leaves remain wet and increases the likelihood of brown patch development. Irrigation after midnight to mid-morning is preferable, because these are the hours the turf would normally be wet from dew. Irrigation in these early morning hours does not extend the leaf wetness period and allows the leaves to dry throughout the day. A light fertilization after a fungus epidemic may speed turfgrass recovery.
Another way that you can help keep this fungus out of your lawn is to keep your mowing height around 3″. We have always recommended that this is a good, healthy height for ‘tall’ fescue! NC State spends a lot of money and resources to make sure that we all have the most accurate information to have the best lawns possible. Even they have stated the following with regards to brown patch, “mowing heights below 2.5″ increase disease development by reducing the plant’s ability to produce energy, whereas mowing heights higher than 3.5″ create a turf canopy that is dense, matted, and holds moisture for extended periods.” So, keep your mowing height to 3″and it will help keep the chances of fungus development to a minimum.