Find the perfect balance when watering trees—it will save their lives
The dog days of summer are officially in swing. Sweltering heat has people everywhere seeking relief in air-conditioned buildings or under a tree’s shade.
Surprisingly, trees need help cooling down and recovering from the excessive summer heat, too. Unfortunately, most people don’t even think about watering trees, the most valuable asset in the landscape.
Well-hydrated trees cope better with the summer’s scorching heat and parched soil. But how much water do they need? And when is the right time to water them?
Most trees are sufficiently hydrated if the upper 12 inches of soil around the tree roots are soaked at least once per week. The rule of thumb is generally five gallons of water for every inch of trunk diameter. Be sure to concentrate on the “drip zone,” the area directly beneath the trees’ foliage.
To ensure the tree is getting just the right amount of water, follow these easy tips from arborists at The Care of Trees, who merged with the Davey Tree Expert Company—and be on the lookout for symptoms to see if the tree needs more or less water. The signs are easy to read and will ensure optimal tree health throughout the summer’s heat.
Tips for Perfect Tree Watering
- The best time to water is in the morning. Run a sprinkler beneath the tree as slowly as possible, use a drip hose, or just apply a slow trickle from a garden hose. Avoid directly irrigating the trunk of the tree, as increased moisture can favor root rot.
- Tree roots are deeper than turf roots, so water about three times as long as you water your lawn to make sure enough moisture reaches the root zone. You should be able to easily insert a long screwdriver 6-8 inches into the ground. A Davey Tree care tip: place a coffee or soup can in the “drip zone” and run the sprinkler slowly until two inches of water has collected in the can.
- “Do NOT build mulch into a volcano,” the Davey Tree experts warn. “This can kill the tree as it cuts off the crown roots and decreases air circulation.”
- Mulch two to four inches around the tree to reduce moisture loss. Mulch should be pulled back 6 inches from the trunk of the tree in a saucer like fashion.
Signs of Under-Watering
- Wilted, drooping or curling leaves that may turn brown at the tips or edge
- A sparse canopy of off-color and undersized leaves, leaf scorch or yellowing
- Untimely fall color and early leaf drop
Symptoms of Over-Watering Trees
- The area around the tree is constantly wet
- New growth withers before it’s fully grown
- Leaves appear green but are fragile and break easily
Fool-Proof Water Check
Still a bit uncertain about the right amount of water? The soil around a tree’s roots tells a story.
Grab a shovel and dig down about 6-8 inches, and pick up a handful of the soil. It should be cool to the touch and slightly wet—but not soaking. If the soil is really wet, it’s a sign of over-watering, so cut back for a bit.
Now, if you don’t have sandy soil, roll the soil into a ball. If it doesn’t hold its shape, the soil is too dry, and it’s time to amp up the watering.
Following these watering guidelines will ensure trees survive the sizzling summer heat and can continue being the most valuable asset in the landscape. When watering, always follow local irrigation ordinances. Questions? Find a local certified tree care specialist at Davey Tree.