Black Knot Fungus In Edmonton

In the Edmonton region, you might notice unsightly black growths on your cherry or plum trees. This is black knot, a common fungus that can make your trees look unhealthy. Here’s what you need to know:

• Black knot is widespread: It spreads easily, and is already fully permitted the Alberta urban forests. Your tree is likely not making the problem worse for others.
• Can’t be cured: Since the growths are just the mushroom portion of the fungus, and the actual fungus lives inside the wood of the tree; once infected the tree will carry the disease for life.
• Not harmful to humans or pets: The growths are not toxic to humans or animals.
• It won’t kill your tree (usually): But it will make your tree look bad and require regular pruning to keep in check. It can also overrun the canopy if not kept in check, in which case pruning will not be a viable option.
• You have choices:
  
  • Manage it: Ongoing pruning can control the appearance but requires regular maintenance. Though this is a viable option, keeping a diseased tree is high maintenance and expensive. 
  • Replace it: Consider removing the tree and planting a healthy tree that isn’t susceptible to the disease. If the tree doesn’t currently bring significant long term value to your landscape; this is the most cost effective choice long term.

Need help? If you’re unsure what to do about black knot, Edmonton Arborist can assess your trees and help you decide on the best course of action.