Feb 23, It is a disease of early spring; as the weather warms and becomes drier, reinfection is unlikely. Even with heavy leaf drop, overall tree health is rarely affected; trees usually send out a second flush of leaves. If a tree has been infected, do what you can to promote growth and avoid stress to the tree. Water the tree during dry periods Estimated Reading Time: 1 min. A healthy ash tree adds 6 to 8 inches of new growth, while infected ashes may only add an inch or less.
What new growth does appear grows sparsely in tufts on the end of branches. Before the leaves defoliate, they turn pale green or yellow or prematurely take on fall colors. Ash yellow can kill an ash tree if the disease is not controlled.
Answer: The leaf drop is probably due to anthracnose. Anthracnose is a common fungal disease of trees in Iowa. Anthracnose may occur on ash, sycamore, maple, oak, walnut, and other deciduous trees (see encyclopedia article Anthracnose on shade trees). Cool, rainy weather in spring favors anthracnose development. It may result in heavy defoliation and twig death. It is common after a rainy season as the conditions favor the growth of fungus. Its symptoms include brown or purple blotches on mature leaves usually during early spring.
The premature leaves often drop from the lower branches. The leaf tissue starts developing a twisted or wrinkled shrubdisposal.buzzted Reading Time: 8 mins. May 17, Many people have noticed leaves falling from their ash trees and are worried the trees are dying. They can stop worrying, according to Joe Zeleznik, North Dakota State University Extension Service forestry specialist.
“The leaves are falling due to a fungal problem called ash anthracnose” Zeleznik says. “Ash anthracnose occurs every year, and this year it’s especially.