Rough Watering Guidelines for Trees

– Spring through Fall –
As a general rule of thumb, most trees require 10 gallons per caliper (diameter) inch of trunk per
week. This total water requirement per week needs to be divided into three or more separate
watering’s per week to get the total water required. For example, a 3” caliper tree would need
roughly about 30 gallons total per week if you watered the tree 3 times per week with the
garden hose you would give the tree around 10 gallons of water per time to equal the total of 30
gallons per week.
Trunk Size 1.5” = 15 Gallons Per Week = 2 Gallons Per Day or 5 Gallons 3x Per Week
Trunk Size 1.75” = 17.5 Gallons Per Week = 2.5 Gallons Per Day or 6 Gallons 3x Per Week
Trunk Size 2.0” = 20 Gallons Per Week = 3 Gallons Per Day or 7 Gallons 3x Per Week
Trunk Size 2.5” = 25 Gallons Per Week = 3.5 Gallons Per Day 8 Gallons 3x Per Week
Trunk Size 3” = 30 Gallons Per Week = 4 Gallons Per Day or 10 Gallons 3x Per Week
Trunk Size 3.5” = 35 Gallons Per Week = 5 Gallons Per Day or 12 Gallons 3x Per Week
Trunk Size 4” = 40 Gallons Per Week = 6 Gallons Per Day or 14 Gallons 3x Per Week
For Evergreen trees a similar scale can be referenced using the trees height instead caliper.
5’-6’ = 15 Gallons, 7’-8’ = 25 Gallons, 9’-10’ = 35 Gallons, 11’-12’ = 45 Gallons and so on.

For Drip Irrigation System ONLY
Drip – Set to water 30 min per day (drip is not on watering restrictions so can run as often as you
need) Emitter sizes per perennials, shrubs, and trees
o (1) 1gph emitter for #1 size perennials / grasses
o (1) 2gph emitters for #3/ #5 size shrubs / grasses
o (2) 2gph emitters for 1.5”-1.75” / 5’-6’
o (3) 2gph emitters for 2.0”-2.5” / 7’-8’
o (4) 2gph emitters for 3.0”-3.5” / 9’-10’
o (5) 2gph emitters for 4.0”-4.5” / 11’-12’
For Clumps add sizes of each trunk to calculate correct watering amount.
Plus, in the Summer, water once a week in addition to drip, give it a deep soak by hand watering.


Did you know that one FOOT of snow equals one INCH of water?
The great state of Colorado faces long, dry periods during the fall
and winter which may result in injury to our trees if we don’t take
the initiative to water. Newly planted trees generally need about 10
gallons of water for each caliper inch of the tree (you can measure
the trunk with a ruler). This means that a 2” diameter tree needs
approximately 20 gallons of water per watering! Water should be
applied slowly, allowing the water to soak into the soil to a depth of
12 inches or more. Water should be applied at several locations
under the drip line and beyond if possible. We recommend that you
apply water to all your newly planted trees once per week if there is
no snowpack on the ground and the temperature is above 40
degrees Fahrenheit. If it is very cold for one whole week, skip that
week and water twice the following week!


As most know, a typical winter day is normally sunny and around 60
degrees Fahrenheit. Due to the angle of the sun during winter, trees
see more intense sunlight which will heat up the southwest facing
trunk of a deciduous tree. The heat on trunk will cause cells to
become active, which will then freeze and become damaged when
the temperatures drop below freezing at night. Sunscald may
appear in trees as sunken or discolored bark, which may crack and
fall off later to reveal dead tissue underneath. Young deciduous
trees (non-evergreen) are the most susceptible to sunscald. Thin
barked trees such as honey locusts, fruit trees, ashes, oaks, maples,
lindens, and willows are at highest risk. To prevent sunscald on
trees, they should be wrapped in commercial trunk wrap of a light
color. Beginning at the base of the tree, wrap upwards to a point
just above the lowest branches, overlapping 33 percent with each
turn. Secure the ends of the wrap by taping around the trunk with
electrical tape. Do not use duct tape or other similar tapes as this
may result in girdling. In April, remove the tree wrap. Newly planted
trees should be wrapped for at least two winters after being planted
or until the bark becomes “rough”.