Peach Leaves Dropping Mid-Summer

Q. I planted a Mid-Pride variety of peach in late spring. Didn't really start showing signs of stress until late summer. I believe it was getting sunburned and it had messed up bark. I cut it away after one branch died. Shortly after this, even though the bark appeared to heal up fine, the leaves started turning yellow and red and dropping from the tree and its getting worse.

A. Mid Pride peach is excellent for our climate and has terrific flavor. The development of red and yellow leaves in peach during hot summer months, and then dropping from the branches, might be the variety of peach, it's tolerance to summer heat or irrigation, particularly if it misses an irrigation.  

This peach went through drought in mid summer just as the reader talked about. Some of the leaves turned red before they dropped.

            Some varieties develop only yellow leaves that drop from the tree while other varieties may develop red and yellow. Think of various fall colors in shade trees. The peach variety called Earlitreat for instance commonly drops its leaves after harvest in May but comes back again and produces the following year.

            Missing an irrigation on peach, short term drought, can also favor a disease called shot hole fungus. In our hot, dry climate this disease seldom becomes a serious problem. It attacks the leaves here but seldom attacks the fruit, unlike in more humid climates like peach-growing regions of California.

Shot hole or shothole fungus disease on peach leaves.

           

Another picture of shothole fungus or Coryneum blight.

When leaves drop it is usually followed by a flush of new growth. This flush of growth is a normal response of any tree when dropping its leaves unexpectedly. However, after dropping the leaves it is important to water normally and not water more often. Watering more often, thinking the soil is too dry, can cause some serious problems to the tree if the roots cannot “breathe”.

            Trees can have a shortage of water for other reasons than not enough water in the soil. Anything blocking the flow of water from roots to the leaves can cause the tree to act like there is not enough water in the soil. It does not necessarily mean that you are not giving the tree enough water.

            If there is severe damage to the trunk and limbs preventing water from reaching the leaves can also result in drought. Damage from borers feeding just under the bark of limbs can cause this limb of the tree to act like it is not getting enough water.

            Drought caused by the feeding of borers inside limbs will cause one or two limbs to die during the heat of summer. Before they die, leaves may turn yellow or red. Trees affected by short term drought usually put on new growth after the leaves drop and water is restored.

            Unless you are seeing some actual limb death I would not pay too much attention to it. Assume it may be a temporary problem with your peach growing in our climate. Let's see what happens to it over the next couple of years. If the fruit was not good I would tell you to pull it out and replant with a different variety. But I know this is a good peach variety.