Tree Troubles Aren’t Always as They Appear By Jonathan Heaton, Bartlett Tree Experts
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s an arborist I work with a lot of people who care deeply about their trees and shrubs. Almost once a week, I will get a call from someone who is alarmed that something new they’ve noticed on their tree might be a major problem. Sometimes it is a problem that needs help, but often it is something that looks worse than it is. Here are some of the common issues that arise. Leaf and twig galls — Some insects and mites lay eggs inside of leaves or twigs with a chemical that causes a swollen area, called a gall, to form. This provides a nice place for the egg to grow into an adult. Most of the time, these are not significant enough to harm the tree and no treatment is needed. However, treatment may be warranted if the majority of the leaves are heavily dam-
aged, or if a lot of branches and twigs are dying. Seasonal needle drop in evergreens — Evergreens shed their leaves, just like deciduous trees, but instead of 1 season, the needles will last for 2-7 years, then turn yellow and fall. This can look pretty alarming, especially on white pine, but it is normal. It is still worth taking a close look because several fungal diseases will cause early needle loss. Normal needle loss will have needles that are uniformly yellow, whereas diseased needles will have black spots and uneven coloration. Dead branches — Trees naturally shed branches, and some species are more prone to this than others. Honey locust, ash, pin oak, and birch are good examples. As long as the leaves have normal color, size, and density, there is no issue. Be on the lookout for several branches dying from the tip back, as this is a sign of a problem.
Smooth patch on a bur oak
Moss and lichens — Trees provide habitat for many other organisms, including mosses and lichens that grow on the trunk and branches. These are not causing any harm.
Anthracnose on an ash
Sapsucker damage — Sapsuckers are a type of woodpecker that drill lines of holes on the trunk to feed on the sap and the bugs it attracts. Most of the time, a healthy tree can deal with the damage. Bugs — There are enough bugs in the world to keep etomologists busy for several lifetimes. Watch for damage to the plants, and become familiar with the common culprits for plant damage in your area, but realize that most bugs you see are harmless. Smooth patch — This is found especially on bur oaks. Fungi feed on the rough, dead outer bark of the tree, leaving smooth patches. This doesn’t cause any harm to the tree. Anthracnose and leaf spot — Anthracnose and leaf spot are generic terms for fungi that damage the leaves of plants. Oaks and ashes are the most common trees to see anthracnose. Look for distorted and curled leaves with black and brown dead spots. Leaves affected by anthracnose will fall from the tree in late spring to early summer. Unless the tree has lost a majority of its leaves or is severely impacted for more than one year in a row, treatment is not generally warranted. Treatments are available for severe cases, or Tree Problems continued on page 22 July | August 2014
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