As the name suggests, Summer Patch typically occurs during the hot and humid summer months, particularly in areas with poor soil drainage or heavy thatch buildup.

It affects cool-season grasses, such as:

• Kentucky Bluegrass
• Tall Fescue
• Fine Fescue

Symptoms include yellowing and browning grass with patches of dead or dying turf. These patches may be circular or irregular in shape and can range in size from a few inches to several feet in diameter.

Summer Patch is caused by a fungus called Magnaporthe poae, which attacks the roots and crown of the turfgrass plant. Damage from this disease will often occur where the grass receives direct sun and is located:

• On south-facing slopes
• Near sidewalks, driveways, or buildings
• Other stressed areas

In the cool weather of autumn, the grass may begin to grow into these dead areas again.

HOW CAN I CONTROL SUMMER PATCH IN MY LAWN?

Summer Patch is very difficult to control, as it thrives in hot and humid weather conditions.

A thick, healthy, well-maintained lawn is the best line of defense. Here’s how you can adjust your beneficial cultural practices to reduce the spread of Summer Patch:

• Hold Off on Watering: Under normal conditions, your lawn should be watered for 30–45 minutes per area, twice a week, ideally in the early morning so the grass dries before nightfall. When a disease is active, though, it’s best to pause watering. Extra moisture can actually help the disease spread.

• Skip Mowing When Possible: Try not to mow while the disease is active. If mowing can’t be avoided, be sure your mower blade is razor sharp. A dull blade can tear the grass tips and spread the disease further. Throughout the growing season, stick to a regular mowing schedule and keep your lawn between 2½ and 3½ inches tall. During the hottest weeks of summer, letting it grow up to 4 inches can help protect the turf. And remember, never remove more than one-third of the grass blade in a single mow.

• Fertilize Consistently: Routine applications of Weed Man’s specially formulated, slow-release granular fertilizer help ensure your lawn gets the nutrients it needs. These treatments are carefully timed to nourish your lawn without the risk of over-fertilizing.

• Consider Core Aeration: Core aeration can make a big difference by improving soil drainage and reducing the chances of lawn disease. It also helps relieve soil compaction, allowing water and nutrients to reach deeper into the soil where your grass needs them most.

In most cases, the spread of the disease will be reduced by changes in weather, but you can also adjust some cultural practices to improve the health of the lawn and limit the spread. However, depending on the size of the infestation and the scope of the damage, other forms of control may be necessary, and you may need to repair heavily damaged areas with sod or the appropriate grass seed.

Your local Weed Man professional may be able to offer additional solutions and recommend the best available treatment to improve your lawn's condition.