Canker, techniques and organic treatments to avoid it

Infecting most ornamental plants such as cypress, willow or fruit trees such as peach trees, apricot trees or cherry trees, canker is a fungal disease that attacks the branches and even trunk of the tree.

Very quickly, branches seem to waste off.
They dry up, die off and often sticky gum flows out of wounds.

Conditions leading to appearance of canker

Necrosis in a branch on a mango tree.This fungus particularly loves moisture. It will tend to spread when the weather is hotter than usual and moisture due to previous rains is still present.

Whenever the tree is wounded, ensure the wound is as clean as can be. If a saw was used, remove the frayed, jagged line at the bark cut with a sharp knife or billhook. It’s like whittling away the frayed ends to make the cut smooth. If not, healing takes longer and canker will more readily appear.

How to fight against canker

  • Preventive care – spraying Bordeaux mixture helps to effectively reduce risks.
    This is performed starting in September, and must be renewed three times for a month and a half (every two weeks).
    In spring, spray once or twice starting in March, again with a fortnight between sprayings.
  • Curative care – remove infected branches immediately and burn them.
    If the trunk itself is hit, remove as much of the contaminated surface as you can with a repeatedly disinfected billhook or sharp plane, until reaching the healthy portion of the bark.

Trees that are vulnerable to canker

Fruit trees vulnerable to cankerMassive canker on a fruit tree.

Ornamental trees vulnerable to canker


Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Canker on a fruit tree branch by Scot Nelson ☆ under Public Domain
Canker in a fruit tree branch by Scot Nelson under Public Domain
Large canker on a fruit tree by Hans Braxmeier under Pixabay license