Ask an Arborist: Why Should a Leaning Tree Concern You?
Q: My tree is leaning. Should I be concerned?
A: Having a tree lean over your house, patio or pool is concerning, to say the least.
However, not all leaning trees should be deemed an imminent hazard to your home. While you should always consult an arborist before removing a leaning tree, there are several factors to take into consideration.
Knowing the tree species and its natural growth tendencies will help determine the overall likelihood of failure. A leaning Crepe Myrtle isn't much of a threat compared to a leaning, mature Red Oak. Look for clues that help indicate what caused the tree to lean in the first place. Clues such as: soil heaving on the opposite side of the lean, mushroom growth near the base, and/or newly rubbing branches with neighboring trees are all indicators the tree's root system may be damaged.
In many cases, a tree will grow outward rather than upward toward the sunlight. A natural lean may mean your tree is unbalanced. But a lean could also mean your tree has grown this way due to extreme weather patterns (ex: northern winds) and is now better prepared to withstand environmental stresses.
Get to know your landscape and avoid root damage at all costs. If a tree was straight and then begins to lean, ask yourself what has changed that may have caused the lean. Did trenching for installation of irrigation, underground drains, construction, or utility lines occur that may have damaged root systems?
Pruning of leaning trees to minimize overall spread can help mitigate the risk of it falling, but always make sure to consult an arborist first to be safe!
-Getth Nelson, ISA Certified Arborist