Fungal Canker on Young Evergreens: When Pruning Isn't Enough

Spraying Oil Won't Stop a Fungus

If the canker is caused by a fungus (most are), Bonide All Seasons Spray Oil is ineffective. Pruning out infected branches is the only mechanical control, but if decay has spread extensively through the wood, the tree cannot be saved—it’s time to replace.

Decision Point

If you’ve already pruned so much the trees are deformed, and the disease keeps advancing, removal and replanting with a resistant species is the practical choice.