Monitoring, and maintaining tree health, is probably the most important of all. Some of the big trees that fall the fastest have existing problems that have been missed or ignored, like decaying tree trunk cavities, root rot, or structural deficiencies that could have been corrected with cabling and professional pruning.
Professional pruning usually includes thinning, which helps reduce the tree’s wind resistance and likelihood of a blowover. It also removes dead branches and gets the tree on its way to closing over, or what is called “compartmentalizing” the wound. Trees don’t regenerate tissue like human beings do, they enclose and grow over areas where branches have been removed, one of the reasons you shouldn’t leave branch stubs when pruning. That being said, you should leave the swollen area at the base of a branch, known as the branch “collar” since the tree has some natural defenses within that area.
Anytime you see conks on a tree trunk (some people might think of them as mushrooms) that should alert you to internal decay in the tree trunk, which weakens it and makes the tree more vulnerable to splitting in high winds.
Images on the news often point out another fact about trees, whether healthy or not, that being that most of a tree’s roots are within the top 18 to 24 inches of the soil, or as it sometimes appears, the tree was “sitting on a thin dime.” Not all trees are as deep rooted as many people believe, and it causes problems for trees to have soil placed over top of their root zones, with some trees being more sensitive to soil fill than others.
And then of course, going back to square one, making the right choices in the trees you plant, will have a huge effect on how well your trees weather storms (no pun intended). While ornamental Pear trees are hugely popular due to their rapid growth, shiny green leaves, nice shape, and white flowers (even though some Pear blossoms really stink), the Bradford Pear in particular tends to split, once it has reached that perfect size and shape. Bummer!
Some of the fast growing Maples create weak V- shaped crotches, which are also more prone to splitting. If you have made any bad choices in trees, the follow up maintenance with proper pruning becomes all the more important. Many trees are “topped” when they should be removed.