Everything You Need to Know About Cytospora Canker [infographic]

Plant diseases and fungi can threaten the health and beauty of the plants, trees, and bushes on your property. One of the most infamous — Cytospora canker – has the potential to minimize the value of your trees and make them more susceptible to damage. Luckily, there are things you can do as long as you know exactly what Cytospora canker is, what to look for, and how to manage this common tree disease.

• What it Is—Caused by the fungus Cytospora kunzei, this destructive disease is notorious for damaging the Colorado blue spruce and the Norway spruce, but it can also affect other spruce species. Typically, the disease progresses from lower to higher branches, making the leaves and branches unsightly. In most cases, Cytospora canker harms trees over 15 years old, but it can occasionally affect younger trees.
• Signs & symptoms—Many times, Cytospora canker is inconspicuous because the affected bark does not experience major colour changes. But there are still subtle signs you can look for:
  • Purplish white or amber patches of resin show up in places where cankers exist
  • Browning needles
  • Dry, brittle twigs replace healthy branches
  • Tiny, black, pin-headed fruiting bodies appear underneath the thin layer of outer bark
• Management—Cytospora canker is not a death sentence for your trees as long as you manage the outbreak appropriately. The following mitigation strategies can help:
  • Removing infected branches at the trunk, always sterilizing the pruning tool between removals
  • Only pruning the affected branches and foliage when dry to reduce spreading more spores
  • Investing in proper soil management and irrigation to prompt vigorous growth