While we know that trees are part of our living world, we often don’t think of them as organisms that can get sick – until it’s too late. Another surprise to most homeowners is that it’s actually rare to find a completely disease-free tree. That’s because there are so many organisms – some microscopic and others quite large – that live on and around these landscape staples. But how can you tell if the trees in your yard are merely fighting off a literal bug or pose a real hazard to your family’s safety? Here are some key signs The United States Department of Agriculture recommends that you look for to check the health of your trees. If you see any of these signals, they recommend that you contact an arborist to assess the situation.
Think green. It may seem obvious, but healthy trees have a canopy of lush, thick leaves. If you think your leaves are lagging, check out other trees in the immediate neighborhood. Make sure you are comparing apple trees to apple trees, so to speak, by looking at trees of the same species. Be aware that individual trees may be late bloomers or lose their leaves a little earlier, depending on their age, ratio of sun to shade, and exposure to the elements.
Dead wood. This is the most obvious sign of a sick tree. These lifeless, leafless branches are brittle and break easily. They lack the resilience of healthy limbs, and thus present a real hazard to anyone or anything that is under them during a wind or ice storm. Contact a professional to safely remove these limbs immediately and assess your tree’s overall health.
Uneven growth. Just like a bad haircut, the most common cause of uneven growth is poor pruning. Poor tree architecture also may be caused by storm damage. Uneven growth can be dangerous if it causes the tree to lean excessively or if there is a large branch that is out of proportion with the rest of the canopy.
Cracks and weak unions. Cracks are deep splits that go through the bark into the wood of a tree and indicate that the branch is already falling. Weak branch unions are places where branches are not securely anchored to the tree because bark has grown between the branches, acting as a wedge. In either case, contact an arborist to identify the extent of the damage and address the issue.
Decay and cankers. Trees typically decay from the inside out, leaving a hollow cavity that weakens the overall structure. Look for fungus or mushrooms on branches or trunks that may indicate this issue. Cankers are spots on branches or trunks where bark is missing that are generally caused by wounding or disease. Be aware that branches are more prone to break near cankers.
Deep-seated issues. Root problems are not as easy to detect, but may be the most dangerous. Just like being unstable on your feet can cause you to fall, weak roots can cause a tree to blow over in a windstorm or even buckle under its own weight. Some root issues are obvious, as when utility work uncovers and severs roots. Others are far more subtle, like long-term damage caused by root decay. Look for changes in the tree, like smaller, off-color leaves or young branches dying off, as potential signs of trouble.
With just a little attention, you can keep your trees looking and feeling great, and serving as a vital part of your outdoor living spaces for years to come.