Gaeumannomyces graminis var. avenae

What is Take-All Patch?

Take-All Patch is a serious root disease of cool-season turf, particularly creeping bentgrass. Caused by the fungus Gaeumannomyces graminis var. avenae, it attacks roots, crowns and stolons, reducing the turf’s ability to take up water and nutrients. Patches can start relatively small but can grow up to 15cm per year. Quite often reoccurring in the same place year after year.

Because the disease develops below the surface, significant root damage often occurs before visible symptoms appear.

Symptoms of Take-All Patch

Above Ground

• Yellow, bronze or reddish-brown patches.
• Turf appears drought-stressed despite adequate moisture.
• Patches gradually increase in size and may become thin or sunken.
• Weed or poa annua invasion is common in affected areas.

Below Ground

• Dark brown to black roots.
• Reduced root mass and rooting depth.
• Blackened crowns and stolons.
• Turf plants pull easily from the soil.

Conditions That Favour Disease

Take-All Patch is most commonly associated with:

• High soil pH (above 6.0).
• Manganese deficiency.
• Poor drainage and excessive soil moisture.
• Young bentgrass stands.
• Turf under environmental stress.

Infection typically occurs during cool, moist periods in autumn and spring, with symptoms often becoming visible during warmer weather.

Management Strategies

Improve Rootzone Conditions

• Maintain soil pH between 5.5 and 6.0.
• Avoid unnecessary lime applications.
• Correct manganese deficiencies (if applicable).
• Improve drainage and minimize prolonged soil moisture.
• Use acidifying nitrogen sources where appropriate.

Fungicide Applications

Preventative fungicide applications provide the best results, particularly during autumn infection periods. Applications should be watered into the rootzone to target the pathogen where it is active.

A preventative program is significantly more effective than attempting to control the disease after symptoms appear.

Key Takeaway

Take-All Patch is primarily a root disease, making early detection and prevention critical. Maintaining an acidic rootzone, balanced nutrition, good drainage and a proactive fungicide program are the most effective ways to reduce disease pressure and promote healthy turf recovery.

Message the team at Lawn Addicts about the best professional lawn care products available online to control Take-all Patch.