The Texas summer heat is a lot of stress on newly planted trees and shrubs. You cannot rely on just your sprinkler system for your watering, especially in the hotter months. Deep root watering has got to be done the old fashion way, with your water hose. Keep in mind that water quantity is significant depending on the time of year. How long you need to water varies on the plant’s size: the larger the root ball, the longer you will need to water. If you let them get too dry, it can cause severe damage to the plant, which sometimes is irreversible. Watering your newly planted shrubs and trees on a schedule for the first two years will ensure a strong start for them in the beginning and less stress. It may be a bit of extra work, but you will reap the benefits down the road.
Below is a short 2 1/2 minute video that offers helpful advice on watering trees
The Amount of Water
To determine the amount of water: take the gallon size of the container the tree or shrub came in and divide by 4.
For example a 45 gallon tree, needs about 11 gallons of water each time.
The Frequency of Water: