Sprawling, vibrant green turf is a telltale sign of summer. But much like any other landscape element, turf requires a certain amount of care to maintain its health. Proper irrigation and mowing are the cornerstones of healthy turf, however it is also important to identify which insects or diseases can harm turf, and these are often difficult to detect.
Seeing The Signs
Insect infestations or disease spread can cause turf to become sunken, brown, and dry, creating an unappealing appearance. Identifying the signs of infestation or disease as early as possible can help stop the spread of turf disease or insect infestation before it causes severe damage. Here are some common insects and diseases throughout the U.S. that affect turf during the summer.
- Dollar Spot (first photo)— This disease affects nearly all cultivated species, especially bermudagrass. Look for these signs:
- Small, sunken brown patches that are around 4 inches in diameter
- During the morning hours, you’ll notice white, cobwebby fungus
Dollar Spot is active during the late spring, summer, and early fall mainly in the Midwest, Northeast, and South. It’s encouraged by prolonged periods of wetness from rainfall, irrigation, dew, etc.
- Red Thread (second photo) — This common disease is very prevalent on lawns in the Midwest and Northeast containing fine fescue and perennial ryegrass, especially if turf is lacking nutrition. Keep an eye out for:
- Patches of browned turf around 5 inches in diameter during the early/late summer
- Pink, fluffy fungus on the leaf blades during the early morning hours
Fortunately, plants typically recover once the conditions are no longer conducive for disease development.
- Brown Patch (third photo)— Perhaps the most destructive disease on tall fescue lawns during Northeastern and Midwestern summers. This disease thrives when nighttime temperatures are less than 68 degrees Fahrenheit with prolonged periods of high humidity. Brown Patch can look like:
- Distinct tan lesions with a dark brown border
- Patches 6 to 24 inches in diameter can sometimes appear when conditions are highly favorable for symptom development
- Lawn is interspersed with blighted leaf tissue which can often be mistaken as drought
- Gray leaf spot (fourth photo)— This disease is especially destructive on St. Augustine lawns during the summer months in the South. It is characterized by:
- A general thinning of the turf
- Close inspection of the leaves will reveal small, gray lesions with a dark border
- Chinch bugs (fifth photo)— These small insects can be a problem during the summer months, on lawns containing Kentucky bluegrass or fine fescue in the Midwest or St. Augustine grass in southern regions. These pesky insects:
- Use their piercing-sucking mouths to extract the juices from the stem of the turf
- They cause turfgrass plants to turn yellow then brown
Because of this, chinch bug damage is often misidentified as drought. In lawns with a history of chinch bug damage consider a preventative treatment.
- White grub (sixth photo)— These insects can cause significant damage to almost all turfgrass species in the late summer, especially in the Northeast and Midwest. It is important to remember:
- White grubs are the larval stage of beetles, such as Japanese beetles, masked chafers, and European chafers.
- White grub infestations may initially look like drought damage with discolored and wilted turf
- Grubs are white, C-shaped larvae that feed in the root zone