Q. I put four African sumac trees in our backyard last September. I am watering them now every Tuesday, Thursday and Saturday for 20 minutes. About two weeks ago the leaves turned brown and fell off. If this continues will the tree lose all its leaves?
A. You can be watering newly planted trees and they can be suffering from drought at the same time.
Container and boxed trees are grown in soils that are totally different from the soils in the landscape. Container soils are looser and lighter than landscape soils.
When these trees are planted, the soil is pushed in around the root ball and, if you are lucky, the plants are watered in twice with a hose. A basin is placed around the trees so they can be given additional water until they are established.
Irrigation emitters are sometimes placed too far from the trunk and the water from the emitters wets the landscape soil but it does not move into the root ball because the soils are totally different from each other.
How to correct this? Always, always, always water newly planted trees and shrubs with water from a hose directed on top of the soil and at the base of the tree. Never, never, never rely on an irrigation system by itself to deliver the water where it is needed after an installation.
Hand water with a hose twice a week. Supplement the water from the hose with your irrigation system on the same days you water by hand. Select your irrigation days and give the plants a rest (no applied water) for one or two days between irrigations.