I phoned for some information from the soil conservation department and my suspicions were confirmed. Salt pollution of soil along highways is greatest at the end of winter. Saline water retards growth and causes "foliar" browning, death of flower buds, twig dieback, or outright death.
Species that are most prone to damage include Sugar Maple, Balsam Fir, Beech, Red and White Pine, and Eastern Hemlock. Those with high tolerance include Horse-Chestnut, Red and White Oak, Black and Honey Locust, and Staghorn Sumac. The birches, other maples, Aspen, Cherry, Basswood, Hickory, and Elms fall some- where in between.
Whereas the Hemlocks and Pine show browning during the same winter, it is obviously later that you notice damage in the hardwoods. They may show light green or yellow foliage, marginal scorch on leaves, and twig dieback. The Sugar Maples assume fall colors early and leaves are shed earlier than those of healthy Maples.
If you are planning to plant a tree along town or state roads, do research on your specie selection. If you have a favorite tree that is being affected by salt, here are a few things you can do:
1. Alter the drainage pattern away from the tree
© 2001 by David Mather. All rights reserved. No parts of this publication may be reproduced in any form or by any means without the written permission of the author.