Tree Diseases: Identification and Removal
Trees get sick just like people. Knowing the signs helps you protect your property before disease spreads to other trees.
Dutch Elm Disease
What it is: A fungal disease that kills American elm trees quickly—often within a single season.
Signs to watch for:
- Wilting leaves in summer
- Branch dieback (especially on one side of the tree)
- Yellowing or browning foliage
What to do: Infected trees should be removed immediately before beetles spread the disease to neighboring elms.
Oak Wilt
What it is: A fungal disease causing rapid decline in oak trees, particularly red oaks.
Prevention:
- Only prune oaks during winter (November-March)
- Never wound oak trees in summer
- Remove infected trees promptly
- Avoid oak-to-oak wood chips
Emerald Ash Borer
What it is: An invasive beetle that has devastated ash trees across Illinois, causing near-total mortality.
Signs:
- D-shaped exit holes in bark
- Canopy dieback starting at the top
- Woodpecker damage (birds feeding on larvae)
Reality: Infested trees die within 2-4 years and should be removed before they become hazardous.
Anthracnose
What it is: A fungal disease affecting sycamores, dogwoods, and maples, causing brown spots on leaves and branch dieback.
Impact: While trees often recover on their own, severe cases may require removal or pruning.
When to Call a Professional
Contact an arborist immediately if you notice:
- Cankers (sunken areas on branches/trunk)
- Significant dead branches
- Discolored or wilting foliage
- Pest damage or unusual holes
Early detection saves trees and prevents expensive removals. Regular tree inspections and professional care keep your landscape healthy and safe.