When your tree trunk turns black, it can cause concern. Why is my tree trunk turning black?
As a premier tree service in Lake City, FL, the Top Tier Tree Specialist crew delves deeper into potential black tree trunk causes and highlights several tips on saving trees with blackening bark.

Common Reasons a Tree Trunk Would Turn Black
If your tree trunk turns black, the tree probably has an insect infestation or tree bark disease causing blackening. Common culprits include:
Fungal Infection
Steganosporium ovatum, a fungus that turns tree trunks black, causes black structures that cover the tree’s bark. These structures initially appear as independent black pustules before they merge to form a solid black layer over the tree’s surface.
While a heavy infestation warrants tree removal, you can implement proactive management strategies to mitigate the spread of the fungus, potentially saving trees with blackening bark.
Sooty Mold
As insects feed on trees, they sometimes leave excretions behind that create ideal conditions for sooty mold to grow. Sooty mold forms a black, powdery coating on the tree’s surface. Regular tree inspections can help identify black mold on your tree trunk.
Fortunately, you can address the issue promptly with non-toxic insecticides and horticultural oil sprays.
Bacterial Cankers
Why is my tree trunk turning black? When you have an already weakened tree, bacteria may cause the growth of black pustules. These pustules eventually form black layers. Pruning and spraying the tree with fungicides might help.
Verticillium Wilt
This rather deadly fungus grows on a tree’s branches or leaves, forming black streaks on its trunk. Typical symptoms of verticillium wilt include sudden wilting and brown spots around the margin of the tree’s leaves.
Gloomy Scale
Gloomy scale, an insect infestation, causes bumpy textures, branch dieback, and a thinning canopy, and it can also contribute to problems such as a splitting tree trunk. Experts often apply horticultural oils during the tree’s dormant months and spray insecticides in early spring to manage the issue.
Insect Infestation
If you have an insect infestation causing blackening on trees, look out for:
- Bark beetles
- Ambrosia beetle
- Carpenter ants
Seek Professional Help
While some measures may give your tree a second lease on life, consulting with an experienced tree care professional to assess the tree and determine the condition’s severity proves the best course of action.
If the situation remains salvageable, the tree health expert can implement reliable solutions designed to nurture your tree back to full health. If not, they can help you remove the tree professionally.
Trust Your Local Tree Care Experts
At Top Tier Tree Specialist, we understand the unique and diverse ecosystem that characterizes North Central Florida. Our skilled crew possesses the tools and knowledge to tackle any tree-related task, including:
- Certified arborist services
- Tree removal and stump grinding
- Emergency tree service
- Tree trimming
Reach out to our experienced staff for more information on topics like “Why is my tree trunk turning black?” or to learn all about tree fungus.
Call Top Tier Tree Specialist at (352) 472-8733 to request a free estimate for tree service in Lake City, Florida, or nearby areas.
