You don't mention where you are, or how long your trees have been in the ground. What is your soil like? In Texas there is a drought. If your trees were newly planted in Texas this year, then you should be watering them enough to keep them from drying out...Your Gater bags probably are not good enough considering the size of your shumard trees. Use a hose, if possible.

For new transplants, watering deeply (as you are) 2-3x a week is good. Also, once a month I would give them each a gallon of seaweed with a few drops of superthrive in it. It's a good for root stimulation.

Where do you live?

Call around to the nurseries in your area. Or come see me at North Haven.