How-To Features Tree Registry Register your trees for customized advice. Fall Care Kits Prepare your trees and shrubs for winter with this kit containing specially formulated fall fertilizer and the TreeHelp Bug Band insect trap. They are typically foliar diseases but twigs, branches, and buds may also be affected. Twigs and branches may develop cankers or dead areas that girdle the stem, causing death of distal parts of the stem. Premature leaf drop commonly occurs on infected trees.
Weakened trees become more susceptible to environmental stresses and secondary pathogens.
In ash trees, buds, leaves, and sometimes twigs can become infected. In early spring, infection of buds or expanding leaves results in irregular brown blotches and distortion of leaflets. These blotches are often associated with leaf margins. Infections that occur once leaves have already expanded result in small brown circular lesions. As these lesions enlarge, they may coalesce.