Red Thread

Red thread is a common fungal disease in western Washington lawns.

It develops rapidly during cool, moist weather (between 50 and 60 degrees, fall through spring). Over-watering and light, drizzly rains foster development of the disease and make it more difficult to control. The disease spreads by rain, wind, mowers and other equipment.

Red thread disease is primarily cosmetic and rarely kills turf grasses. It can be effectively controlled by good lawn-care practices. It is not effective to use fungicides to treat red thread in western Washington.

Symptoms

Red thread generally appears as water-soaked, darkened patches varying from two inches to 24 inches or more. The leaves gradually become bleached or scorched-looking. The disease moves from leaf tips down the blade. When advanced, you can see fine fungal threads, pinkish to bright red, in bright light conditions.

What you can do

Wash the underside of your mower between mowing cycles with a diluted solution of chlorine bleach or hydrogen peroxide and let it dry.
• Keep mower blades sharp so they cut, rather than tear, the grass.
• Red thread can be tracked from lawn to lawn. If you have a lawn mowing service, ask them to clean the mowers between lawns.
• Review your watering procedures. Less frequent watering for longer periods is better. Keep the turf adequately watered in summer to maintain lawn health.

What In Harmony can do

• Apply balanced fertilizer. A good fertilization program is critical in controlling red thread. We will increase fertilizer applications according to severity.
• Apply liquid micronutrients to help strengthen lawn health.
• Apply calcium to help with soil acidity and to help unlock available nutrients trapped in your soil.
• Aerate the lawn to keep plants healthy and aid in nutrient uptake.