Problems With Silver Leaf Maple Trees

Silver leaf maple trees are native to the eastern United States and Canada. They grow approximately 80 feet tall with a 60-foot spread. They are hardy in USDA zones 3 to 9 and are often planted as shade trees because of their ability to adapt to many soil types and moisture levels. Silver leaf maples are susceptible to a number of pests and diseases.

The verticillium fungus causes a disease called verticillium wilt. Infected trees have stunted or yellow leaves, leafless buds and branches that suddenly wilt and die in one area of the tree. The larger branches develop green or brown streaks in their sapwood. Trees with verticillium wilt may die quickly within several weeks or may die more slowly over several years. The disease is more prevalent among trees that are stressed by poor growing conditions or drought.

The K. apocrypta fungus causes a foliar disease called anthracnose. The fungus spends the winter in dead leaves on the ground. It creates new spores during the spring when the weather is cool and moist. The wind and rain spread the spores to trees, causing new infections. The leaves develop reddish-brown patches that grow together and kill large parts of the leaf. New growth turns black and shrivels, and adult leaves fall prematurely from the tree. Anthracnose is usually an aesthetic problem. Most healthy trees recover and grow their leaves back without suffering any permanent damage, according to the University of Illinois Extension.

Maple bladder-gall mites hibernate in the buds or beneath the bark of silver maples during the winter and enter the leaves in the spring. Their infestations trigger the growth of abnormal plant cells. Round, wart-like growths form on the upper surfaces of the leaves. The galls are usually between 1/8 and 1/16 inch and are light green, but they turn pink and finally black as the disease progresses. Infestations cause cosmetic damage such as leaf distortion and defoliation.

Cottony maple scale insects are flat, drab, purplish-brown insects that prefer silver leaf maple trees. Young scale insects crawl out on the leaves after hatching. They attach their mouth parts to the leaf's surface and suck out the plant juices. Cottony maple scale insects leave cottony-white masses filled with a thick, sap-like liquid. The popcorn-sized masses attract a black fungus called sooty mold that interferes with photosynthesis. Cottony maple scale causes leaf yellowing, defoliation and branch or twig dieback. Repeat infections can cause tree death.