Brown patch is a disease of the soil which attacks the leaf, and results in killing the lawn. It presents as round damaged circles ranging in size between 5 cm and a metre in diameter. The colouring begins as yellow and continues to darken as the turf dies.
The most noticeable characteristic of Brown Patch is a smoke like ring which circles the affected area. Although this is not always present, and usually disappears with increasing warmth of the day, and winds.
Brown Patch usually appears and flourishes from a combination of over watering, night time watering, and warm nights. It appears from Spring through to Autumn.
STOP: Are you sure you have brown patch disease? Brown, bare or dying patches can occur in lawns for many reasons, try also checking other articles in the Lawn Care and Lawn Repair sections.
Environmental conditions must be right for the Brown Patch pathogen to take hold and the disease to flourish. The same conditions that causes a disease to flourish, usually causes a weakness in the turf, making the disease strong and the turf too weak to fight it. With proper cultural management of our lawns we want to create an unfriendly environment for the disease so it won't take hold, and if it does, to reverse the situation.
Excess Humidity
Water lawns only in the morning. We don't want a lot of moisture sitting in the thatch layer overnight during warmer weather.
Lawn Thatch
Mow lawns regularly and control excessive growth habits to reduce the build-up of thatch, and vertimow when necessary to remove any thatch build-up.
Low Nutrient Levels
Fertilise all year round with a quality, balanced fertiliser in small amounts applied regularly.
Shade
Cut back surrounding bushes or trees to allow a lot more direct sunlight to the area.
Soil Compaction
Monitor compaction, and rectify human patterns causing quick compaction. Core or aerate the lawn when required.
The easiest way to treat this disease is to begin a proper fertilising program immediately, and bring cultural management practices in line with proper standards. Water levels should be monitored, as excess water will increase the problem.
A healthy lawn with correct nutrient levels will aid in prevention and ridding your lawn of Brown Patch.
Chemical treatment with a fungicide can be purchased and applied to aid in eradication.
Even if the brown patch disease is brought under control from correct Cultural Management practices, the pathogen responsible for the disease can still survive in the ground for many years, and will re-emerge when environmental conditions improve for its survival.
For this reason, it is vitally important to continue correct lawn care throughout the year, and on an ongoing basis, as well as to consider an application of the correct fungicide designed to eliminate brown patch.
Highly respected Australian turf and plant breeder Todd Layt shares expert lawn care advice with homeowners on The Lawn Guide.