If you’ve spotted a long crack running up your tree and searched online for answers, the leading provider of expert tree services in Charlotte Hall, Maryland, would like to help you understand what causes a tree trunk to split vertically.
Hernandez Complete Tree Service helps local property owners determine the severity of tree problems and what to do about them. The good news is that most splits are treatable when you catch them early.
Here Are the Most Common Reasons Tree Trunks Split Vertically in and Around Charlotte Hall
We sit in a climate zone where winters bring sunny, mild afternoons followed by sharp overnight freezes. That temperature swing is the primary driver of splitting tree trunks in our area, and it affects more trees than most property owners realize.
Frost Cracking
During a warm winter day, sunlight heats the outer bark and the living tissue just beneath it. When temperatures plunge after dark, the outer layers cool and contract faster than the inner wood.
That difference in contraction rates generates enormous internal pressure, and the trunk tears open along its weakest point, often on the south or southwest side. Water inside the cells freezes and expands during this process, adding to the stress.
Sunscald
Sunscald follows a similar pattern but develops more gradually. Winter sun warms the bark enough to awaken dormant cells. When freezing temperatures return, those cells die.
Over time, the dead tissue peels away, leaving vertical strips of damaged bark that can eventually split open. Thin-barked fruit trees and young ornamentals are the most vulnerable.
Lightning and Storm Damage
Lightning superheats sap beneath the bark, turning it to steam and blowing a vertical groove up the trunk. Heavy ice loads and high winds can also twist the trunk enough to cause splitting, particularly in multi-stemmed trees and species with included bark such as Bradford pear and silver maple.
Preexisting Damage
Old pruning wounds, lawn equipment scrapes, and animal damage all create weak points in the trunk. When environmental stress arrives in winter, those compromised spots become the first place the wood gives way. This pattern is consistent across residential yards throughout Southern Maryland.
Rapid Growth Stress
Heavy fertilization that promotes rapid growth, or a wet season following a drought, can cause the inner wood to expand faster than the bark can accommodate. The result is a vertical split from the inside out. Red maple and tulip poplar are among the species most prone to this in the region.
How To Tell Whether the Split Threatens the Tree
A narrow crack on an otherwise healthy tree often calluses over with new growth and poses little long-term risk. The situation becomes more serious when a crack:
- Runs deep into the tree
- Keeps reopening each winter
- Shows signs of fungal growth or insect activity
- Appears on a tree that already leans toward a structure
An inspection by an experienced arborist gives you a definitive answer.
What Not To Do
Sealing a vertical crack with foam or wound paint traps moisture, accelerating internal decay. Trees heal from the edges inward on their own. Instead, keep the area around the base mulched and watered during droughts, and have a certified professional evaluate any damage before taking further action.
Get Expert Help From Hernandez Complete Tree Service
If you’re concerned about what causes a tree trunk to split vertically, contact Hernandez Complete Tree Service for an on-site assessment. Our team handles everything from inspection and pruning to emergency removals, and we can advise you on proper mulching methods around tree trunks to support long-term tree health.
Call (240) 299-4639 or contact us online today to request a free estimate.