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Cankers take many forms

Cankers are typically caused by fungi infecting the trunk. They typically begin with a trunk or branch injury which opens the cambium to infection. There are no treatments for cankers. Keeping trees healthy can sometimes help trees outgrow the fungus infection. Prevent cankers by not injuring the trunk.

classic canker on tree
The classic canker begins as a circle and expands as the tree attempts to grow around the infection. Sometimes these sunken area can be elongated instead of canker on ficus
Black canker on ficus displays as a tar like substance on the bark.

hypoxylon canker

Hypoxylon canker shows as a black or gray crusty patch on the bark. This fungus is common and causes infection as a secondary agent after the tree was weakened by drought, lightning, root cutting, or some other stress.



chinese elm wiht phyophthora

The base of Chinese elms and some other trees becomes infected with Phytophthora causing cracks or sunken areas on the lower trunk.

fusarium fungus on yellow pine

The Fusarium fungus on southern yellow pines form deep cankers on trunk and branches. This may not kill the tree but the tree can break at this point.