- Home
- Trees & Shrubs
- Watering Trees
How To Water Trees?
Water trees slowly and deeply at the drip line, about 10 gallons per inch of trunk, so the soil is moist 12 inches down. Learn the methods that work.
Water trees slowly and deeply at the drip line, the ring of soil under the outer branches, until the soil is moist about 12 inches down. A common guide is 10 gallons per inch of trunk width for each deep watering. Young trees need this weekly, while mature trees need it only in dry spells.
On this page
Watering a tree is not like watering a flower bed. A quick spray with the hose barely wets the surface, while the roots that matter sit a foot or more below.
Trees need deep, slow water that soaks down into the root zone. Done right, one good watering can last a young tree a week and a mature tree several weeks. Here is how to do it.
Step 1: Find the roots
Most of a tree's water-absorbing roots are not right at the trunk. They spread out wide, often well past the edge of the branches, and most live in the top 12 to 18 inches of soil.
The best place to water is the drip line, the circle of ground under the tips of the outer branches. For young trees, water the area from near the trunk out to just past the drip line.
Step 2: Know how much to give
A common rule is about 10 gallons of water per inch of trunk diameter, measured about knee high, for each deep watering.
| Trunk width | Water per deep soak |
|---|---|
| 1 inch, newly planted | About 5 to 10 gallons |
| 2 inches | About 20 gallons |
| 4 inches | About 40 gallons |
| Large, mature tree | Many hours of slow soaking in drought |
Step 3: Water slowly
Water poured fast runs off before it soaks in. These methods all deliver water slowly:
- A soaker hose ring. Lay it in a circle at the drip line and run it for 1 to 2 hours.
- A slow hose trickle. Set the hose on a thin trickle and move it to a few spots around the tree.
- A bucket with holes. Drill 2 or 3 small holes in the bottom of a 5 gallon bucket, fill it, and set it near a young tree.
- A tree watering bag. These slow-release bags zip around young trunks and drip water out over several hours.
Step 4: Water on the right schedule
Newly planted trees need deep water once a week for their first 1 to 3 years, and more often in the first month. Established trees usually manage on rain, but need a deep soak every 2 to 4 weeks in long dry spells.
Evergreens also need a deep watering in late fall, before the ground freezes, to prevent winter burn.
Step 5: Mulch to keep the water in
Spread 2 to 3 inches of wood chip or bark mulch in a wide ring around the tree, out to the drip line if you can. Keep it a few inches from the trunk. Mulch slows evaporation, cools the roots and stops grass from competing for water.
For tree-specific timing, see our guides to new trees, fruit trees and evergreen trees.
Watering Trees FAQ
How long should I water a tree?
Usually 30 minutes to 2 hours with a slow trickle or soaker hose, enough to wet the soil about 12 inches down.
Is it better to water trees in the morning or evening?
Morning is best, because less water evaporates and the soil has all day to absorb it. Evening watering at the roots is also fine.
Do mature trees need watering?
Usually not in normal weather. In a long drought, a deep soak every 2 to 4 weeks helps mature trees stay healthy.
We turn horticulture research and real growing experience into plain-English watering schedules you can actually follow.