How To: The Fundamentals of Watering

Water is essential to keeping trees healthy. It is key to their growth, and it also helps trees fend off disease, survive droughts, and withstand insect attacks.

Using the proper technique conserves water, and ensures that your trees will be healthy and happy for years to come.

• For young, newly planted trees, apply water over the root ball and the planting area just outside of the root ball. This is especially critical for the first few years when new roots are developing.
• For mature trees, water within the root zone. The root zone can spread three times as far as the edge of the canopy (also known as the dripline), so don’t water just at the base of the tree. If you are in doubt, a safe bet is to water the area between the dripline and trunk.
• Do not allow a sprinkler system to splash water on the trunk or leaves. Trees do not absorb water through their trunks, so not only is it wasted water, but the accumulation of moisture can also lead to disease and decay.
• Keep the root zone moist but not soaked. It is imperative to remember that too much water is as bad as not enough water.
• Use an open-ended garden hose, soaker hoses, or for newly planted trees, consider a tree-watering bag (such as a Treegator) to slowly and consistently provide water to the root system. Slow, deep soaks are most effective because it allows the water to percolate down into the root system.
• Don’t have soaker hoses or a tree-watering bag? Larry Eacret, a Treecologist at Leaf &amp Limb, suggests the following rule of thumb: Measure the trunk diameter at knee height using a ruler or yardstick. Then follow this simple watering formula: tree diameter × five minutes = total watering time. For example, a tree with a 3" diameter would be 3 × 5 = 15 minutes of watering. Repeat 2-3 times a week.
• If that does not work for you, here is another good watering rule: provide your tree with 8 to 10 gallons of water per week for every inch of trunk diameter. So a 6” caliper tree would need around 60 gallons per week.
• It’s also important to remember that trees need more water in hot months and less in cool months.
• Finally, the best time of day to water is first thing in the morning before harsh sun comes in contact with the tree. Watering this early will prevent evaporation and ensure that the tree has enough water during the hottest hours of the day. The second best time to water is later in the evening when the sun is going down.

Please note that these are only general guidelines. Watering needs will vary based on species, climate, time of year, weather patterns, and more.

Have any specific watering questions? Have a tip we haven’t listed here? Send us a message. We love to hear how you’re keeping your trees healthy and happy.