Silver Maple Tree Diseases
A rapidly growing variety of maple, the silver maple (Acer saccharinum) is a medium-sized deciduous tree that often lives for more than 130 years. It grows best in moist conditions along stream and river banks, flood plains and the edges of lakes. It is often sold as lumber along with red maple. Because of its attractive foliage and rapid growth habit, it is widely planted as an ornamental in urban areas. The sap of silver maple has been collected for use in maple syrup, although its sap contains less sugar than the more commonly used sugar maple.
Verticillium wilt (Verticillium albo-atrum) is a stem disease that can cause sudden death of silver maple trees. Symptoms include yellowing and defoliation of leaves on a few branches or even the entire tree. Leaf edges roll inward prior to turning brown if the tree is severely infected. Verticillium wilt is hard to eradicate and the best defense is to plant resistant cultivars. Complete removal of infected trees will eventually control the disease locally; verticillium wilt cannot survive more than 3 years in the soil without a host plant. Some success has been achieved with chemical control, although these may need to be professionally applied in order to be effective.
A fungal disease that affects many varieties of shade trees, anthracnose (Gloeosporium spp.) attacks all varieties of maple trees. The symptoms begin as reddish-brown lesions which then coalesce, killing large areas of the affected leaf. The young shoots and leaves then shrivel and blacken. Severe infections can lead to defoliation. The disease is spread in spring to new growth from previously infected tissue. The best way to control anthracnose is to remove fallen leaves and twigs, which reduce populations of the disease that overwinter. Remove dead twigs and branches and improve air circulation by selectively pruning out crowded branches to let air into the center of the tree's canopy. Keep your silver maple in good health by watering and fertilizing regularly. Healthy silver maple trees will recover more readily from a serious infection than those under stress.
Shoestring Root Rot
A common fungal disease that affects evergreen and deciduous trees worldwide, shoestring root rot (Armillaria mellea) can live for years on the roots of its host plant undetected, until producing its crop of mushrooms at the base of the tree. The tree will previously exhibit reduced growth with yellowish leaves and twig dieback, including the tree suddenly or gradually dying. The appearance of the tan mushrooms at the base of the infected silver maple tree is what distinguishes this disease from others with the same distressed leaf and twig symptoms. Efforts to control the spread of this disease have proven ineffective, due to the wide range of the rhizomorphs that spread this fungi.