Mature trees increase property value by as much as 10%, according to the U.S. Forest Service. But a tree can shift from asset to liability when branches, trunks or roots suffer injury and threaten to cause property or personal damage.
By inspecting trees and addressing potential problems, you can protect your home, save lives, and safeguard the investment that healthy trees add to your property. Not sure where to begin? Use our checklist to identify possible hazards in tree growth and development.
Potential hazards include:
Broken and dangling branches – including broken branches lodged in the canopy
Dead branches – easiest to spot during the growing season since leaves will be absent
Branches missing bark or growing fungus – both signal dead wood
Cracks where branches attach to trunk
Narrow crotch angles where branches attach to trunk –weak and prone to breaking; common with Elm and Maple
Action to take:
- Remove dead wood as soon as possible and at any time of year.
- Monitor branches you suspect are dead.
- Hire a certified arborist to remove large or dead branches located high within a tree canopy and to inspect trees with narrow crotch angles.
Cracks or cavities
Oozing or bleeding
Cankers (create missing or sunken bark)
Fungal growths along the trunk (indicate decay)
Multiple upright trunk stems with a tight V-shape at their juncture (U-shape is stronger)
Action to take:
- Consult with a certified arborist to determine tree health. Any of these symptoms can diminish a tree's stability.
- The exterior of a tree may appear fine except for a small crack, cavity or fungus, while the interior may be rotted, soft or even empty. An arborist has tools to inspect a trunk's interior.
- Multiple upright trunk stems are prone to breaking. A certified arborist may suggest inserting cables to reinforce narrow crotch angles and prevent breaking.
There are two types of roots: anchoring and absorbing.
- Anchoring roots are big, woody roots that literally support the tree. Some are visible above ground; some aren't. When anchoring roots are damaged, the tree can appear healthy with green leaves. It may lean – or not. But compromised anchors mean even a gentle wind or the weight of rainwater on leaves can topple the entire tree.
- Absorbing roots are mostly invisible and absorb water and nutrients from soil. When absorbing roots are damaged, the problem usually manifests above ground as small or discolored leaves.
Look for these symptoms or causes of root problems:
Fungus or mushroom growth on anchoring roots, along the base of the trunk or on soil near the tree (fungal growth indicates decay)
Cavities and hollows in visible anchoring roots
Cracked or raised soil on one side of a tree trunk (could indicate the start of leaning)
Recent construction or disturbance that has cut or crushed more than half of roots beneath a tree
Excessive soil fill, or planting beds that are too deep (more than 2 inches), that can smother absorbing roots
Action to take:
- Consult with a certified arborist to determine tree health.
When To Inspect
Inspect trees annually, any time of year. Also make a quick inspection following severe storms.