Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Turf > Irregular patches > Other

Print Icon Email Icon Share Icon

Turf > Irregular patches > Other

1 of 6
  • Image: drought 1
  • Image: drought 2
  • Image: drought 3

Heat and drought stress

  • Occurs when temperatures are high (greater than 85° F) and little or no moisture is available through rain or irrigation for at least 2 to 3 weeks
  • General browning of entire turf grass area; may also look thin and dry
  • Affected areas may have clumps or tufts of green grass within areas of tan dry grass
  • Occurs often in sunny, exposed lawn areas but can occur in dry, shady areas as well
  • In most cases, cool season grasses will turn green and resume growth once cooler conditions and more frequent rainfall return
  • If heat and drought stress have been severe for several weeks, affected lawn areas may not recover or may only partially recover
2 of 6
  • Image: shade 1
  • - CLICK PHOTO TO ENLARGE -

Shaded areas

  • Turfgrass stand sparse with varying amounts of soil surface exposed
  • Generally grass blades thinnes and of paler color compared to sunny areas
  • Powdery mildew as evidenced by a white 'powder-like' material commonly present on grass blades
  • Sparseness of the lawn worse near trunk of tree, closer to a north wall, or in other heavily shaded areas; may be no grass at all in these areas
  • More information on Shaded areas...
3 of 6
  • Image: sod webworm 1
  • Image: sod webworm 2
  • Image: sod webworm 3

Sod Webworm

  • Symptoms first appear late spring and mid to late summer as small (size of a quarter) ragged brown areas
  • Damaged areas can become larger and coalesce with each other
  • Adult moth is 1/2 to 3/4 inch long, buff-colored with snout, active spring and mid-summer
  • Larvae are 3/4 to 1 inch long full grown, brownish to grayish with black spots, active late spring and mid to late summer
  • More information on Sod Webworm...
4 of 6
  • Image: billbug 1
  • Image: billbug 2
  • Image: billbug 3

Bluegrass Billbug

  • Damage most commonly seen during July and August
  • Damaged areas yellow, then turning brown or straw-colored in small, irregular patches
  • Particularly common near sidewalks, driveways, and other sources of heat
  • 1/4 inch long, gray to black beetle with long, curved snout, active spring and late summer
  • More information on Bluegrass Billbug...
5 of 6
  • Image: cutworm 1
  • Image: cutworm 2
  • Image: cutworm 3

Cutworm

  • Grass blades clipped in spring (sometimes later in summer)
  • Scattered areas of thinning and/or browning grass, which can grow larger
  • Dark-colored caterpillars up to 1 1/2 to 2 inches long
  • More information on Cutworm...
6 of 6
  • Image: red thread 1
  • Image: red thread 2
  • Image: red thread 3

Red Thread
Laetisaria fuciformis

  • Irregular to round patches of tan grass 2 to 24 inches wide
  • Grass blades die and turn tan from the tip down and are often mixed with healthy grass blades
  • In humid weather, clumps of pink cotton candy-like fungal growth can be seen on infected patches of grass
  • Hard pink to red thread shaped fungal structures emerge from the tip of infected grass blades
  • Common in cool, wet weather and N-deficient grass

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy