Tree Watering Guidelines

How much water should I give my young tree?

How much time will it take to water my tree?

See our “Types of Watering Methods” section below for more information about each method in the above chart.

Check whether your tree species has low, moderate, or high water needs on Canopy’s tree library.

May to October generally has almost no rainfall. If spring or fall is unusually wet or dry, irrigate accordingly.

Water-efficient methods:

Hand-watering: A good choice for establishing young drought-tolerant trees. Create a soil basin within the drip line and SLOWLY fill with water from a hose or bucket. Allow water to soak in and repeat two to three more times. See Caring for Young Trees for further instructions on basin watering.

Drip irrigation: To use water most efficiently, install a drip irrigation system or convert your sprinkler system from spray to drip. With these methods, water is applied at a slow rate directly where it’s needed near the tree roots. Soaker hoses can be a cost-efficient alternative.

• When possible, give your trees their own dedicated irrigation valve, since trees require deeper watering than ground covers or shrubs. For a new system, tap into an existing hose bib. Consult with your irrigation contractor or bring a layout diagram of your property to your local hardware store or irrigation supply house to get advice.
• The chart in “Watering Guidelines for Young Trees” and “Watering Guidelines for Mature Trees” assume drippers are placed approximately 3’ apart, with an application rate of 1 gallon per hour (GPH).
• Soaker hoses have variable output. Check depth of watering and adjust time as necessary to water the tree to a depth of 18 – 24” for most mature trees.
• Top mulch should be applied over drippers to a depth of 3 – 5”

Bubblers: This localized watering method allows water to saturate the soil at ground level and deliver water to the root system.

• Higher flow bubblers are recommended for newly planted trees to achieve even coverage. Install 1-gallon-per-minute (GPM) emitters. Maintain a solid watering basin that can hold 10 to 15 gallons. If necessary, split run time so water does not overflow the basin.

Watering methods to avoid when possible:

Sprinklers and spray irrigation: These methods apply water at a fast rate, resulting in water loss due to runoff and evaporation. If you have an existing sprinkler system, however, there are ways to make it more water efficient:

• Do not rely on overhead sprinklers to water trees. The water does not penetrate deep enough to encourage the tree to create deep roots for support. This can also encourage trees to affect the infrastructure and lift up sidewalks searching for water. Conventional spray heads apply approximately 2.0 inches of water per hour.
• Lawn irrigation: Does not water trees successfully. It generally reaches only the first few inches of soil, encouraging trees to form weak “surface roots.”

Tips for making spray irrigation more efficient if you have to use it:

• Replace nozzles with water-efficient models. These apply water more slowly, which gives water more time to soak into the ground, saves water, and reduces runoff. One start time is adequate with this method.
• Break water run cycles into smaller periods in the same day—this allows more water to penetrate the soil. For example, use two 20-minute periods separated by a brief rest (to allow water to soak in), rather than one 40-minute period. Most irrigation controllers can be adapted to do two start times automatically.
• Apply only 1 inch of mulch If you are using spray irrigation, use only 1″ of top mulch so that water can still penetrate.
• Drip and soaker hoses are always preferred over spray irrigation because they are more water efficient (less water loss to run-off or evaporation).
• Converting a lawn: If you choose to convert your lawn to a drought tolerant landscape remember to continue supplying the tree with supplemental water using a bubbler or a drip system.

• As your tree grows, move nozzles farther out from the trunk, and consider removing additional lawn.
• Adjust watering frequency and duration. Water thoroughly, but less frequently, allowing the soil to dry out between waterings.
• Inspect your irrigation system every spring to look for leaks or clogged spray heads or drippers. Move drippers away from the tree as it matures, always apply water at or near the drip line of the tree and slightly beyond.