In many parts of North America, people will soon enjoy one of nature’s finest shows – fall foliage. Color-changing leaves make for a beautiful display, but early changes in leaf-color can be a sign that your tree is stressed and is susceptible to insect and disease attack.
If the leaves on your trees seem to have gotten a jump-start on fall compared with those on similar trees in the area, you might want to consult a professional arborist who can identify any problems and offer possible solutions.
“Premature colors can be an indication that a tree isn’t vigorous enough to withstand insects and disease organisms that may attack it, not to mention the usual changes that occur when the weather turns cold,” says Tchukki Andersen, BCMA, CTSP* and staff arborist with the Tree Care Industry Association. “Occasionally, only one or two limbs of the tree will show premature fall color. This could be a sign of a disease at work, weakening only the infected limbs.”
The more common situation is for the entire tree to exhibit premature fall coloration, a phenomenon usually linked to root-related stress. “Trees respond to these stresses by trying to curtail their above-ground growth,” adds Andersen.
Leaves can be thought of as small factories containing raw materials, products and by-products, all in chemical form and some with color. As the leaf is “abandoned” by the tree, the green chlorophyll – the dominant chemical found in most leaves – is broken down and “recycled,” leaving behind other-colored chemicals. Supply lines to the leaves also become clogged. If the major chemical remaining in the abandoned leaf is red, the leaf turns red. If it’s yellow, the leaf turns yellow, and so on.
“The yearly variation in color intensity is due to varying weather conditions, which can affect the balance of chemicals and their composition in the leaves,” Andersen says. Differing amounts of rainfall, sunlight, temperature, humidity and other factors may have an effect on how bright, how quickly and how long the “leaf-peeping” season will be in any given year.
Find a professional
A professional arborist can assess your landscape and work with you to determine the best course of action. Contact the Tree Care Industry Association (TCIA), a public and professional resource on trees and arboriculture since 1938. It has more than 2,000 member companies who recognize stringent safety and performance standards and who are required to carry liability insurance. TCIA has the nation’s only Accreditation program that helps consumers find tree care companies that have been inspected and accredited based on: adherence to industry standards for quality and safety; maintenance of trained, professional staff; and dedication to ethics and quality in business practices. An easy way to find a tree care service provider in your area is to use the “Locate Your Local TCIA Member Companies” program. You can use this service by calling 1-800-733-2622 or by doing a ZIP Code search on www.treecaretips.org.