bonsainotwar

I live in Albuquerque.Ihad this problem recently on a cherry,a buckeye,and a collected apple.The apple died. Here's an article I found on the web,that might be some help to you...


When Trees Drop Their Leaves or Develop Early Fall Color
By Doris Taylor
Plant Information Specialist
The Morton Arboretum
August 8, 2002

Trees will sometimes develop a premature fall color or drop leaves for no apparent reason.Trees that commonly exhibit this behavior include maple, tulip tree, birch, linden, and elm.This often causes alarm for homeowners as they wonder if this is a sign that their tree is dying.

A sudden drop of healthy leaves is sometimes hard to explain. It usually occurs during or shortly after a period of hot, dry weather following a very wet spring and lush growing conditions. Trees that are established during optimum growing conditions in spring may actually develop an over-
abundance of leaves.Then, as the tree comes under more stress from heat or dry periods, it is not able to maintain the excess foliage and an abrupt drop of leaves occurs. This is a natural effort by the tree to maintain a balance between root and top growth. Such leaf drop is not a sign of dying.

On the other hand, not all mid-summer leaf drop or early coloration is natural nor harmless.Newly planted trees or trees in poorly drained sites may have limited root development because of an overly wet spring.One of the first symptoms some trees show when root damage has occurred is leaf scorch.Dead brown-yellow spots develop on the leaves and as the scorch progresses, major portions of the leaf margins will brown and die. The plant is not able to take up enough moisture through the roots to keep the expanded leaves completely active and alive.

This same scorch may not be totally a result of root damage or lack of root growth. Anything that interferes with water movement in a plant, such as cankers, over-fertilization, borer damage, or disease can result in a similar symptom. Once the cause has been determined, cultural practices,
such as careful watering during drought periods, may lead to improved growth and plant recovery.

Some summer leaf drop may also be the result of a disease that infected leaves earlier in the season. Summers that follow wet springs often show more leaf drop from disease as the stress on damaged leaves continues. Crabapples, maples, oaks, and hawthorns have dropped leaves this
year in response to the fungal diseases apple scab, leaf spots, anthracnose and rust. If spots are noted on the leaves that have fallen, or are still on the tree, a thorough clean up of diseased leaves in the fall will help to reduce the problem next year. At this time,fungicide sprays are not
beneficial.

Trees under substantial stress, but not severely damaged, may develop premature fall color. Some maples and oaks respond this way. It is not normally a sign of death, but it is an indication that the tree is having difficulty and might need some extra attention.Check for signs of root or trunk disease or insect problems.

Another disease problem that causes premature discoloration or leaf drop is called verticillium wilt. Verticillium wilt is a disease of the vascular system of the plant,which causes blockage of the water conducting cells. Early stages begin slowly as only a few branches decline and drop
leaves.As damage becomes more severe or the stress on the tree increases, these branches may die totally and others begin to drop leaves. The process may take several years or be fairly abrupt.
There is no chemical control for the problem.