Rain, rain, rain. We are so thankful for it, but there are two sides to every story. Our grass loves it and so do our trees, shrubs, flowers and vegetable gardens. However.... rain combined with high humidity, high temperatures, thick grass and limited air-flow at the soil surface brings with it certain challenges that face all of us who work in the landscape:
This time of year is promising to be a busy one as far as brown patch is concerned. At Organic Plant Health we have received a great many cries for help regarding this landscape eyesore. The good news is that Organic Plant Health has 2 very effective controls for turf disease. Both controls represent more cost efficient approaches to disease control for the residential or commercial consumer.
What does it look like? Circular patches ranging in diameter from a few inches to over three feet. Grass has brown lesions on the leaf. Lawn appears "dried out" or wilted.
What conditions cause this? High temperatures, high humidity, and moisture on the lawn for long periods of time. Frequent rain can greatly attribute to disease. Seems to occur more on grass maintained at lower mowing heights.
What to do? Water only early in the mornings. Mow grass at 4 inches. Grass should completely recover as weather conditions become less favorable to Brown Patch growth.
Diagnosis: Brown Patch occurs during the summer and affects all turf grasses. Tall fescues and perennial ryegrasses are highly susceptible to infection. Brown patch primarily affects the leaves of the plant and rarely damages the roots. Brown Patch presents as blighted patches ranging in diameter from a few inches to several feet. The grass has dull brown lesions, which may develop dark, reddish borders as the infection becomes more severe. Commonly, the grass looks "dried out" or wilted. Damage is most severe on lawns maintained at low mowing heights.
Conditions Favoring Development: High temperatures combined with water remaining on the surface for long periods over successive day. When nighttime temperatures remain above 68 degrees Fahrenheit and the leaves remain wet for 8 or more hours per day (including dew on the lawn overnight), infection rates are high. The disease is most active when daytime temperatures are above 80 degrees Fahrenheit. Rainy conditions and high humidity accelerate disease development and activity.
Control: Avoid irrigation in the late afternoon and evening. Early morning watering has been shown to reduce the effects of brown patch. Timing of irrigation has more impact than the frequency of irrigation. Continue to mow the yard on a regular basis and cut the grass higher than normal. As the disease affects the leaves and not the root structure, turf stands should completely recover when conditions become cooler and less humid.
Treatment: Organic Plant Health recommends one of two protocols to control Brown Patch.
1) Combination of Nutrol® & Prudent44™. Combine these two products with water at the recommended rate and apply to the affected area as indicated. Organic Plant Health recommends applying these products every 21 days beginning early to mid May, through August 31st as a proactive treatment. Mix 1.0 oz. of Nutrol™ powder and 0.5 oz. of Prudent44™ per gallon of water to cover 1,000 sq. ft.
2) Nature’s Warrior™. This is Organic Plant Health’s private label product containing multiple strains of beneficial bacteria known to suppress Brown Patch and other diseases affecting turf, ornamental trees and shrubs. This product is 100% natural and 100% safe to apply to your vegetable garden and fruit trees. Mix 0.25 oz. of Nature's Warrior™ powder per gallon of water to cover 1,000 sq. ft.
Other diseases to watch out for: Leaf Blotch, Pythium (root rot), Black Spot, Powdery Mildew.