California flat-top agaricus in Washington
MODERATEFungus
California flat-top agaricus is currently active in Washington. Watch your susceptible trees closely and act early.
About California flat-top agaricus
Growing under shrubs in wood chips. Older fruiting bodies, with some younger baby ones nearby.
Symptoms to watch for
Treatment options
Fungicide Application
Apply systemic or contact fungicide at the first sign of infection. Repeat applications may be needed during wet weather. Follow label rates and timing.
Sanitation and Pruning
Remove and destroy all infected leaves, branches, and fallen debris. Improve air circulation by thinning dense canopy growth. Sterilize pruning tools.
Soil and Moisture Management
Ensure proper drainage, avoid overwatering, and apply mulch to reduce soil splash. Many fungal pathogens thrive in persistently wet conditions.
Recommended Products & Tools
Helpful supplies for managing California flat-top agaricus. Always read and follow label directions, and confirm a diagnosis before treating.
Broad-spectrum protectant for many fungal leaf and bark diseases.
Preventive spray for needle cast, leaf spots, and blights.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Need help with California flat-top agaricus in Washington?
Connect with ISA Certified Arborists serving Washington:
Browse all Washington arborists →Frequently asked questions
Is California flat-top agaricus in Washington?
California flat-top agaricus is currently active in Washington. Watch your susceptible trees closely and act early. It was first recorded here on October 20, 2026.
What does California flat-top agaricus look like?
How do I treat California flat-top agaricus?
Options include: Fungicide Application, Sanitation and Pruning, Soil and Moisture Management. Confirm the diagnosis before treating, and consider a certified arborist for high-value trees.