The health of our environment depends on our ability to observe and assess the condition of our trees. Trees have “spotted” patches of disease, whether they’re trees or bushes. This means that if a tree has a particular symptom, such as brown spots or leaves that are crusty or disintegrated, or if it produces porches, knots, or cracks, you should take note of it and report back to the local authorities or local Arborist. Here are some of the signs and symptoms of a tree being sick.
Has the affected area become less green over time? If you have found discolored leaves on the tree or have observed an odd yellowing of the leaves, this indicates that the tree is sick. Discoloration can also occur in the bark, so if the tree has lost its green foliage (which typically matures in the final year of the tree’s life), it might be sick and should be removed.
Has the tree suddenly lost a significant portion of its leaves? This happens because trees lose their leaves throughout the season. Some reasons for this include snow or wind, making it impossible for the tree to freeze over, the cold wind blowing the leaves off the tree, or simply a small number of leaves that fall.
Is the tree’s leafing decaying? As trees mature, they stop producing new leaves, but before they do, they replace their leaves with decaying ones. This process can continue for a year or longer before new leaves are produced. Therefore, if the tree is sick, then it will have fewer leaves (decay), and the decaying leaves could cause a yellowing of the foliage (called leaf yellowing).
Is there a tree odor? Some trees produce a tree odor as a means of protection. This is not considered a health problem unless the tree produces this scent to warn you of danger (i.e., a falling tree). If the odor comes from a sick tree, it should be removed or treated with a commercial product such as Scotts Oil or Daphnoflagell.
How do I know when a tree is sick? Based on the symptoms that exist for each specific type of tree, it is possible to decide if the tree is sick. However, no matter what type of tree you are examining, the most important thing is that you act quickly when you notice a tree problem so that you can prevent further damage to your property (trees behave very differently if they are threatened by other animals, wind, frost or excessive heat).
Trees should be inspected for problems yearly in warm climates and every few years in cold climates. The best way to determine if a tree is healthy is to simply sit on it or examine its root system, branches, and foliage.