Water only when air temperatures are above 40 degrees F.
Apply water at mid-day so it will have time to soak in before possible freezing at night.
Water is the best treatment to prevent turf injury.
Monitor weather conditions and water during extended dry periods without snow cover—one to three times per month.
Trees obtain water best when it is allowed to soak into the soil slowly to a depth of 12 inches.
Methods of watering trees include: sprinklers, deep-root fork or needle, soaker hose or soft spray wand.
Apply water to many locations under the dripline and beyond if possible.
If you use a deep-root fork or needle, insert no deeper than 8 inches into the soil.
As a general survival rule, apply 10-20 gallons of water for each diameter inch of the tree.
Newly planted shrubs require more water than established shrubs that have been planted for at least one year.
Winter watering should be done from October through March.
Apply 5 gallons two times per month for a newly planted shrub.
Small established shrubs (less than 3 feet tall) should receive 5 gallons monthly.
Large established shrubs (more than 6 feet) require 18 gallons on a monthly basis.
Decrease amounts to account for precipitation.
Read more published information from Colorado State University Here or direct at the link below.