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.
Typically, a garden hose running at a moderate rate will disperse 5–10 gallons per minute. This is an important thing to know about your hose — so test it. Using a 5-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.
For new trees (planted within the last two years) that have trunks less than one inch in diameter, your frequency of watering should be higher; aim for 2–3 times per week. If you are using a garden hose, water the tree for at least 30 seconds to ensure a deep soaking. Remember to keep the water flow at a moderate level. Another option is to use a slow-release tree bag. This type of system can save you time by preventing you from hand watering multiple times per week. That time really adds up when you’re caring for multiple trees!
Established trees should receive a deep soaking during unusually dry periods. Aim for once a week or every other week, depending on how the soil is retaining moisture. Quick tip: Use a trowel to dig six inches deep. Is the soil still moist? If so, you can hold off watering for another day or two.
A great option for watering established trees is a soaker hose. Use the hose in a spiral pattern out to the trees dripline. A common mistake with established trees is to give them frequent, shallow bits of watering focused at the base of the tree. A soaker hose will help you properly soak the full root system of the tree.
Coe Roberts is one of the Arbor Day Foundation’s many certified arborists. For more specific watering guidelines, we encourage you to speak with a certified arborist in your area.