How to control brown patches in your lawn by guest author Stan Baker.
Brown Patch is a debilitating fungal disease that causes large, circular dead areas on the lawns of millions of home owners each year.
Rhizoctonia, the fungus responsible for Brown Patch, thrives at 70 degrees and 70 percent humidity. At or above those conditions, the fungus can wipe out a large area of your lawn, virtually overnight.
The key to preventing Brown Patch is to keep your grass as cool and dry as possible. So how do you prevent this disease during the hot and humid summer months? The following tips from soil agronomist, Stan Baker, will help you keep your lawn from falling victim to this ugly fungus.
Keep your grass short
When your lawn grows tall, sunlight and wind are unable to penetrate the canopy and move the heat and moisture away from the turf’s surface.
The trapped warmth and humidity create optimal conditions for the fungus to grow.
During the warm summer months, keep your lawn mowed to an ideal length: 1-1.5” tall fescue, 0.5-1” Bermuda grass, 1.75-2.5” Kentucky bluegrass, 1.5-2” ryegrass, 1-1.5” zoysia or centipede grass.
Best watering practices
You may be tempted to come home after work and turn on the sprinkler, but don’t! If you water your lawn after 2 pm the moisture will become trapped at the surface right before the hottest part of the day.
Water beneath the canopy won’t have time to evaporate and will heat up past optimal fungal growth temperatures, leaving your lawn susceptible to an outbreak of Brown Patch. Also, don’t be tempted to water at night. The turf will still not be fully cooled until just before dawn.
You don’t have to water every single day. In general, a good watering every three days in the morning will help keep your soil dry as long as possible without leaving moisture at the surface.
Don’t feed the fungus
Like your lawn, fungus likes nitrogen. However, using too much nitrogen fertilizer will weaken your lawn’s natural defence systems while also providing the fungus with more energy – essentially giving fungus an advantage over your grass.
Find a fertilizer program that is right for your local conditions and stick to it. Never use more fertilizer than is recommended.
Promote plant vigour
When you start with strong turf, it is easier to defend against diseases like Brown Patch. If you’re planting a new lawn, be sure to use a premium-grade, Brown Patch resistant grass seed, such as Sta-Green with Nitro-Fuze.
Remember, however, that no grass is “Brown Patch proof.”
Your last resort
At the first sign of Brown Patch symptoms, apply a broad-spectrum fungicide that is labelled for use on Brown Patch. Remember to follow all label and safety instructions, as well as local ordinances, for any product that you apply to your lawn.