Wait to water – if the ground is no longer frozen, and if tree buds are starting to swell, this is a good time to water trees. Established trees and shrubs (two years in the ground) do not require water as frequently as newly establishing plants. Most species will thrive on a good watering (to the root depth) one or two times a month during the growing season (April to September). You may need to increase this frequency to once a week during periods of hot weather. A good guideline for the amount of water is within the range of 38 litres per inch of trunk diameter when measured at 54-inches above grade. Use a regular garden hose or a soaker hose and move the hose frequently to ensure that all the area under the tree’s drip line is saturated. To determine the tree’s drip line, look at where the rain falls from the tree during a rain shower.