Type your question here!

Tuesday, November 4, 2014

Problem With Chitalpa after Deep Root Feeding

Q. We are having a major problem with one of our two chitalpa trees after they were fertilized. We were told by professionals that these are desert trees and don't require a lot of water and the watering schedule has not changed for 2-1/2 years. They are on drip irrigation with each tree receiving 5 gallons of water a day scheduled at 2 AM, 6 AM and 10 PM.
We had a tree service company do a deep root feeding on May 14th because one tree looked sickly while the other one was healthy. After fertilizer was applied the healthy one now has leaves that are brown, curled up and falling off. The tree service came back out and suggested to water the tree for an hour for two consecutive days just in case the fertilizer put the tree into a shock. We did that with no change in the trees except for new shoots growing from the trunk of the damaged one. The tree service doesn’t know the problem. Should we plan on replacing this tree in the near future or will it come back next year?
Chitalpa not the readers
Chitalpa not the readers

Chitalpa not the readers
A. Desert trees need water just like regular trees but their main claim to fame is that they need irrigations less often. 
Let’s explore what happened. First of all, 5 gallons of water a day is not enough water unless they are very small trees, perhaps no more than 5 feet tall.
Secondly, there is no reason to apply the water at three different times when using drip emitters. Drip emitters apply water very slowly so the entire amount of water can be applied at one time with no problems.
I think you may have been a bit misled when you purchased these trees. Many people, including professionals, do not understand the relationship between the water use of desert trees and the level of acceptability these trees have when different amounts of water is applied.
Chitalpa with limb dieback, probably watering issue, not the readers
Just because trees are so-called desert trees does not mean that they can get by with very little water. Chitalpa is a desert-adapted tree, not really a true desert tree like some of the acacias and palo verdes.
I do think your damaged tree resulted from the fertilizer application to the soil. I don’t think there was enough water present in the soil to dilute the fertilizer enough to keep the roots from getting damaged after the application.
Secondly, I believe the soil water taken up by the roots was so high in fertilizer salts that the leaves were damaged and the severely damaged ones fell from the tree.
What can you do? Flood the area under the tree with water once a week for the next three weeks. After this, go back to normal irrigations using your irrigation system. I would look closely at the possibility that you may not be applying enough water during an irrigation.
If you suspect this might be the case, either increase the number of minutes so that more water is applied or add more drip emitters under the canopy if you suspect there are not enough. You will increase the amount of water either way. The key consideration is whether you are applying enough water under the entire canopy or not. If you suspect you are not, then the only solution is to add more emitters.
What will happen to the tree? Because of leaf drop you may have some branch die back and lose some limbs. Let the tree continue to grow this summer and fall and don't do any pruning until this winter.

This winter see if you can do some corrective pruning to improve the shape of the tree. If the tree has been to severely damaged due to die back, then you might consider replacing it. I don't think you can make that determination for another month or two.

1 comment:

  1. Watering is so often misunderstood by homeowners and professionals alike. Think of watering this way - if you are thirsty, do you take out a juice glass and perhaps drink just 3 oz of water or do you grab a good size glass, fill it to the top and drink it all down and perhaps refill the glass? Obviously, you take a big, hefty glass of water and drink it all down at once to take care of your thirst. You don't take a few more ounces later in the day and again at night. That won't take care of your thirst. It does not take care of your trees thirst either. Set your irrigation clock to run for 60 minutes, after sunrise and just once a day. Your trees and plants can get the big drink that they need to get through the entire day and night. You only need to adjust your clock for the seasons, 3 days per week in the summer, 2 days per week in Spring and Fall, and 1 day a week in winter unless we are lucky enough to get a good soaking rain. Remember your emitters are measured in gallons per hour, you likely are only applying apprx. 4 gallons of water at a time, but it is efficient water, a good, deep drink.

    ReplyDelete