WSU Extension


Lawn and Turf
2,4-D damage 
Anthracnose/Basal crown rot 
Brown blight 
Brown patch 
Curvularia blight (Fading out) 
Dog injury 
Dollar spot 
Fairy ring and mushrooms 
Leaf spot 
Microdochium patch (Pink snow mold) 
Necrotic ringspot 
Powdery mildew 
Pythium crown and root rot 
Red thread 
Septoria leaf spot (Tip blight) 
Slime molds 
Take-all patch 
Typhula blight (Gray snow mold) 
Yellow patch 
Chinch bugs 
European Chafer 
European crane fly 
Japanese beetle 
Japanese beetle 
Sod webworm 

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Caption: Pythium crown and root rot
Photo by: R.S. Byther
Lawn and Turf : Pythium crown and root rot
(revision date: 6/22/2015)

Pythium crown and root rot is caused by fungi which can also cause damping-off of new grass plantings. The rot causes a general decline of the turfgrass in patches or in large areas. Symptoms may include poor color, thinning, and slow growth. During the cool, wet conditions which favor disease development, damage may first appear as small, diffuse yellow patches up to 3" in diameter. In warmer, humid weather, damage may first appear as small, brown to tan or bronze areas. Initial patches of either type may coalesce overnight to form large areas of wilted, dying grass. The crowns and roots of infected plants appear watersoaked and root volume and vigor is reduced. Both roots and crowns may be discolored. The fungi typically survive in infected plant tissues and plant debris. They may be spread by infected clippings, contaminated equipment, and water.
Management Options

Non-Chemical Management
  • Good drainage is essential to prevent disease.
  • Provide proper culture including proper fertilization. Do not fertilize heavily in warm, humid conditions.
  • Reduce stress on grass as much as possible.
  • Avoid overwatering. Deep, infrequent waterings are best. Water in the mornings so grass can dry quickly.
  • Remove thatch and aerify as necessary.
  • Collect and remove infected grass clippings to help reduce spread of disease.
  • For more information on proper care of lawns, including mowing heights and fertilizer recommendations, see EB0482E, Home Lawns.
Select non-chemical management options as your first choice!

Chemical Management

None recommended


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Caption: Pythium crown and root rot
Photo by: R.S. Byther
Caption: Pythium crown and root rot close-up
Photo by: R.S. Byther