One of the most frequent questions people have during the warm summer months is, “How should I be watering my trees?” While every tree is going to have specific considerations (e.g. species, location, soil type, etc.), the following are some general guidelines to keep your trees happy throughout the summer.
Do I Need to Water Now?
There’s a simple step you can take to see if your tree needs water. Using a long screwdriver with a minimum six-inch blade, probe into the ground in several locations under the drip line (the furthest edge of the tree’s canopy). If you are having difficulty probing to a six to eight-inch depth and natural rainfall is not in the forecast, then you should begin a watering regime. After watering, use this test to see how you’ve done.
The Bucket Test
Typically, a garden hose running at a moderate rate will disperse 5–10 gallons of water per minute. This is an important thing to know about your hose — so test it. Using a five-gallon bucket, time how long it takes your hose to fill it up. Knowing your hose’s flow rate will help you make informed decisions regarding watering duration for your trees, as the general rule of thumb is to give the tree around 10 gallons of water per inch of trunk diameter.
Young Trees
New trees, or those planted within the last two years that have trunks less than one inch in diameter, should be watered much more frequently than older trees. Aim for two to three times per week. If you are using a garden hose, water the tree for about one minute to ensure a deep soaking. Remember to keep the water flow at a moderate level.
Another option is to use a slow-release tree watering bag. This type of system can save you time spent hand watering multiple times per week. It really adds up when you’re caring for multiple trees!
Older Trees
Established trees, or those two years and older, usually don’t need to be watered quite as often. Aim for once a week or every other week, depending on how the soil is retaining moisture. During unusually dry periods, these trees should receive a deep soaking to stay healthy.
A common mistake with established trees is to give them shallow watering doses focused at the base of the tree. Avoid this by using a soaker hose in a spiral pattern extending out to the tree’s drip line. A long period (four hours or more) using a soaker hose will properly water the entire root system of the tree.
Additional Resources
We hope these tips help your trees thrive this summer. Happy watering!
Pete Smith is an ISA-Certified Arborist with the Arbor Day Foundation. For more specific watering prescriptions for your trees, we encourage you to contact a Certified Arborist in your area.
