301-631-5296


Red Thread

Red thread Red thread occurs during humid periods in spring and fall when daytime temperatures are between 60 F and 75 F. Fine-leaved fescues and some ryegrass are most susceptible, but it also affects Kentucky bluegrass and other fescues. Slow-growing, nitrogen-deficient turfs are particularly vulnerable. Look for water-soaked patches of grass that turn to a bleached tan as grass dies. Patches may be round or irregularly shaped, from about an inch to a foot in diameter. In humid weather, the fungus produces coral-pink to blood-red hyphae up to an inch long on the tips of grass blades. These red threads can disperse the disease to healthy turf by mowing and foot traffic.

To help prevent the disease:

maintain soil fertility, and where red thread has been a problem in the past, lime to maintain pH at 6.5 to 7.0. Avoid overwatering, provide good drainage, and keep grass blades as dry as possible by watering early in the morning.


Prevention includes:

• Proper mowing. Maintain lawn at maximum height and remove no more than a third of the plant when mowing. • Keep thatch less than ½ inch. • Don't over fertilize. Avoid applications before late May or early June. Avoid excess nitrogen, especially in spring. • Avoid frequent light waterings. If you water during dry spells, apply enough to soak in 6 to 8 inches deep. • Choose resistant varieties. Resistant varieties of Kentucky bluegrass and fescues are available.

Leaf Spot

Leaf Spot Leaf spots are most destructive during cold, wet, overcast weather in spring and fall. Look for gradual browning and thinning of grass. Small, dark-brown, purplish, or purplish-red colored spots appear on the leaves from the early spring to late fall. As these lesions increase in size their centers may fade to a straw or light-brown color. The spots are usually surrounded by narrow dark reddish-brown to purplish-black borders. As the disease progresses in favorable weather, the spots run together and girdle the leaf blades. As the weather warms, the crowns, rhizomes and roots may rot. Plants lack vigor and wilt from moisture stress during the middle of the day.

Fairy Rings

Fairy rings Look for an arc or circle of lush green grass and/or toadstool or puffball mushrooms. The rings may be as large as 60 feet in diameter, though most are less than 15 feet. They usually occur in the same place each year, with the ring expanding outward.

The lush grass is from a release of nutrients (especially nitrogen) caused by the fungi. Some of the mushrooms associated with fairy rings are poisonous and should be raked up and removed regularly if small children play in the area. Fairy rings are more of an aesthetic nuisance than threat to lawns. Sometimes there will also be a ring of dead grass caused by the fungus. More frequent mowing can minimize the difference in grass height. More frequent fertilization and heavier watering can even up grass growth and color, but may cause worse disease problem.

Prevention includes:

• Proper mowing. Maintaining maximum height, if possible, and taking off no more than a third of the height when mowing). • Maintaining adequate moisture without overwatering. Minimize leaf wetness by watering early in the day. • Avoiding excess nitrogen. Dollar spot occurs less on nitrogen deficient turf. • Choosing resistant varieties.




Prevention includes:

• Proper mowing. Maintaining maximum height, if possible, and taking off no more than a third of the height when mowing). • Maintaining adequate moisture without overwatering. Minimize leaf wetness by watering early in the day. • Avoiding excess nitrogen. Dollar spot occurs less on nitrogen deficient turf. • Choosing resistant varieties.

Dollar Spot

Dollar spot The name comes from the silver-dollar sized straw-colored spots this disease causes on putting greens. On longer grass, the shapes are more irregular. When dew is on the grass, look for white cob-webby fungus. Blades of grass show straw-colored lesions with reddish-brown borders. Of the common lawn grass, bluegrass and fescues are most affected.

Brown Patch

Look for 6- to 20-inch diameter brown patches, sometimes with a with purplish-gray "smoke ring" border or "frogeye" with green grass in the center. Leaves show tan lesions with brown edges.