Cytospora Canker on Silver Maples: Symptoms and Management

Diagnosis

Two silver maples in Texas with declining spring leaf-out and thousands of tiny bumps on trunk/branches likely have Cytospora canker. Symptoms: discolored bark (yellow to black), sunken cankers with black pimples (fungal fruiting bodies), orange spore tendrils in wet weather, reddish-brown wood discoloration.

Management

No cure for established canker. Prune dead branches. Water and fertilize to maintain vigor. Avoid wounding. Monitor for structural failure. Consider replacement if decline continues.