All Season's Guide to Tree Cankers in Edmonton

It’s important to identify and treat sick trees quickly so you can continue to enjoy them for years to come.

If your tree’s leaves don’t grow back or if a branch falls off, it’s obvious there’s a problem, but tree diseases like cankers are harder to spot. Here’s what you should you know about tree cankers and what you can do to prevent them in your yard.

What is a tree canker?

Cankers are the result of a fungal infection that gets into the tree trunk or branch via a wound. They can lead to branch death or the whole tree becoming weakened and eventually dying. The fungus often appears in the late summer or fall and can become dormant over the winter only to return in the spring.

How to spot a tree canker

Cankers can be hard to identify because they vary in size, shape and colour depending on the type of tree they’re found on and the fungus that causes them. In Alberta, the most common types are canker of spruce and cytospora cankers, which are caused by similar fungi.

  • Canker of spruce 
    Despite the name, this infection can attack tamarack larch and white pine trees as well as spruce trees. The cankers can be identified by localized lesions that are coated with a heavy white substance that may also drip from the tree. The needles on affected branches will turn red or brown, and eventually the whole branch will die.
  • Cytospora cankers
    These cankers affect many different tree species, including balsam, poplar and aspen. Once part of the tree is infected with this fungus, it usually dies quickly, before cankers even have time to grow. Bad-smelling, discoloured and soft wood underneath the bark is usually a sign of this type of canker.

What to do if your tree has a canker

If one of your trees is infected, make sure to remove all affected areas. Prune dead and dying branches with clean pruning shears, and remember to disinfect your cutting tools after each cut so the fungus doesn’t spread. 

How you can protect your trees

Fungal infections tend to target weakened or injured trees. The best way to protect your trees from infection is to help them stay as healthy as possible. Make sure they get regular aeration and balanced fertilization. In times of draught, water them so they don’t dry out.

If you think your tree has a canker or one of the other tree diseases common in Alberta, All Season Tree Service can help. We also provide pruning, tree removal and other tree services in Edmonton and the surrounding areas. Call us today for a free consultation.