Did you water the planting hole thoroughly before planting? If so, water deeply when the soil is dry down to your second knuckle. If you did not fill up the planting hole with water and allowed to drain down and the soil is excessively dry, you need to water deeply but slowly so that the water gets to the bottom of the rootball. You don't want to overwater so thus the soil dryness check! Good luck!
Ouina gives you good advice, JM. Since those are pretty big plants, you may want to invest in Gator bags or another slow-release watering bag to ensure your plants get the deep watering they need to get established. You need to continue this until your ground freezes this winter. Also check out this Hometalk post that provides good guidelines on the quantity of water needed:
Thanks for the comments! When they were planted, I was told to water each plant one minute 3x per week. Would that do the job?
Not even remotely, JM. And a good long soak is much more beneficial than a rapid burst of water.