Die Back In Apricot Trees & A Hedge Got Fried In The Heat

Question:

I’m concerned about my fifteen-year-old Apricot tree.  In the spring the growth is lush and vigorous, but in the early summer one branch or limb will become sick and dies. Eventually, I have little or no tree left.  This is the second apricot tree to decline similarly. What can be done to prevent this?

Answer:

The primary causes of die back in the canopy of apricot trees are Phytophthora Root Rot and Eutypa Die Back.
  • They affect both major and minor branches or limbs, and the disease symptoms look very similar. The one factor that distinguishes or separates the two diseases is when the die back occurs.
  •  Phytophthora Root Rot is a soil borne fungus that attacks the roots of Apricot, along with Cherries, Peaches, Nectarines, Plums, and many other ornamentals.
  • Root rot is the primary suspect when a limb or section of a tree fails to break dormancy and leaf out. It’s the causal agent when for no apparent reason the foliage on a branch collapses or wilts and turns brown shortly after the rainy season concludes.
    • You would expect this problem in clay soils that drain poorly and receive excessive summer irrigation.
    • A good soaking with a large watering basin once every three weeks is sufficient for established apricots as well as other fruit trees, and planting under their canopy is discouraged. Phytophthora Root Rot is a slowly developing disease.
  •  You’ll find more information at  ipm.ucanr.edu/PMG/r107100111.html
  •   However, from your description, I don’t think root rot is your problem. Instead, Eutypa Die Back would be my guess. Eutypa Die Back is only an issue with Apricot trees and grapes.
    • It’s an airborne fungus that enters the tree through the pruning wounds made during the winter months when it’s wet and damp.
    • The affected branches or limbs collapse in the late spring, after Memorial Day, or in the early summer for no apparent reason.
    • You prevent this from occurring by changing the time of the year you prune. It is now recommended to prune Apricots is the late summer.
    • Although the leaves haven’t dropped the tree is going dormant as its growing season has concluded.
  • You’ll find more information about Eutypa Die Back  at ipm.ucanr.edu/PMG/r5100911.html

NOTE:

When fruit trees are under stress, borers will attack, and it’s not uncommon for globs of amber colored sap to be on the limbs and branches. Also, it is possible for an Apricot to be suffering from both of these diseases concurrently.

Question:

Our Privet Hedge burned in the heat while we were on an extended vacation.  There was a problem with the drip system that has now been corrected. It looks sad right now. Will it recover?

Answer:

There is a  good chance that it will improve, but you need to be very patient as it doesn’t happen over night. Right now, I’d do nothing other than removing the burnt/brown leaves as best as you can. You’ll need to wait to see where the new growth develops and then prune off the rest of the damaged growth.  More than likely this may not occur until next spring.