Lawn Disease – Stripe Smut

(Ustilago striiformis)

Stripe Smut is a disease that occurs during cool weather and is caused by the fungus Ustilago striiformis. In the United States, this lawn disease is more common in northern climates, where it typically affects lawns during the spring and fall. It also can show up in southern states during parts of the summer. Stripe Smut sometimes shows up during long periods of cool weather in the spring or fall.      

Identifying Stripe Smut -

Turfgrass plants affected by Stripe Smut are stunted and may appear light green or yellow. The infected grass blades will display yellow-green streaks in the early stages of infection and these streaks later become gray. Shortly afterwards, the leaf tissue over the gray streaks ruptures and black spore masses are exposed.

Towards the end of the Stripe Smut disease infection cycle, leaves may become shredded and point downward if the infection is severe enough. Additionally, damage caused in April-May will often not be seen until June-August.

Conditions for Stripe Smut Infection -

Stripe Smut can only lead to an infection in your lawn if all of the following conditions are present:

1. Pathogen – Stripe Smut (Ustilago striiformis)

2. Host – Poa annua, bentgrasses, Kentucky bluegrass or perennial ryegrass

3. Environment – Warm, dry climates with temperatures ranging from 50-60 degrees Fahrenheit

Stripe Smut Control -

Cultural disease control practices create favorable conditions for a healthy lawn, and often create unfavorable conditions for the growth of Stripe Smut. Environmental conditions cannot be changed, but cultural practices performed by the homeowner can be modified to lessen the chance of extensive damage from Stripe Smut. Scotts LawnService can help determine a plan for preventing and controlling Stripe Smut in your lawn.

For Stripe Smut control and treatment, Scotts recommends the following cultural control tips:

  • Avoid fertilizers with high levels of nitrogen, especially during the summer months
  • Maintain a balanced fertility level
  • Irrigate as needed to prevent drought stress
  • Plant disease resistant turfgrass

Scotts LawnService has professional products that can prevent and control lawn diseases when cultural control practices are not effective.

Scotts LawnService is the trusted industry leader for professional quality lawn care. Our exclusive lawn care products include premium grass seeds and professional-grade fertilizers; our lawn service teams are comprised of highly trained, industry-certified professionals. Contact a representative today for Stripe Smut control options available in your area and to learn how you can enjoy a lush, thicker lawn that only Scotts LawnService can deliver.