Avoid These Tree Watering Mistakes This Summer
Watering your trees might seem straightforward, but small mistakes can lead to big problems—especially during Idaho’s hot summer months. Whether you're in Boise, Meridian, Nampa, or Eagle, understanding how and when to water trees properly can make the difference between healthy growth and long-term damage.
In this guide, we’ll highlight the most common tree watering mistakes, explain why they matter, and share a simple depth test to help you check if your trees are getting the moisture they need.
Why Summer Watering Requires Extra Attention
Summers in the Treasure Valley bring extended dry spells, intense afternoon heat, and increased evaporation. Unlike lawns or flowers, trees—especially mature ones—require deeper and less frequent watering. They depend on soil moisture several inches below the surface, not just at the top layer.
Mistakes like overwatering or relying on quick sprinkler sessions can deprive your trees of essential hydration while promoting shallow root systems and disease.
Common Tree Watering Mistakes
Overwatering
Too much water can be just as harmful as too little. Overwatering saturates the soil and prevents oxygen from reaching the root zone, leading to root rot and fungal issues. Symptoms of overwatering include yellowing leaves, early leaf drop, and a mushy or sour-smelling base around the trunk.
Young trees often suffer from overzealous watering. Once established, most Idaho-friendly trees prefer deep watering every 7–10 days rather than daily soaking.
Shallow Watering
Quick, surface-level watering encourages roots to grow near the soil surface, making trees more vulnerable to drought and wind. Sprinklers designed for turfgrass often deliver too little water to meet a tree’s needs.
Use a soaker hose, tree ring, or drip irrigation system to deliver water slowly and deeply into the soil, targeting the area around the tree’s drip line (the edge of its canopy).
Poor Watering Timing
Watering during the hottest part of the day leads to high evaporation, meaning less water reaches the roots. Morning and evening are optimal, as cooler temperatures allow moisture to penetrate deeply without immediate loss to the air.
Avoid watering late in the evening if temperatures remain high overnight, as this can encourage fungal growth in wet conditions.
Watering Too Close to the Trunk
Tree roots extend well beyond the trunk. Watering only at the base misses the areas where absorption is most effective. Aim to water throughout the entire root zone, especially beneath the outer half of the tree canopy.
Try This Simple Watering Depth Test
To find out if your watering efforts are reaching deep enough, try this basic test:
Wait 24 hours after watering.
Use a long screwdriver, soil probe, or metal rod and push it into the soil around the drip line.
If it slides in easily to a depth of 6 - 10 inches, your watering is adequate.
If resistance occurs before 6 inches, you may need to water more slowly or for a longer duration.
This quick test gives a clear picture of whether your watering strategy is effective, especially during the hottest parts of summer.
Best Practices for Watering Trees in Idaho
For healthy, resilient trees throughout the summer:
Water slowly and deeply once every 7 - 10 days
Focus watering near the drip line, not the trunk
Apply mulch 2 - 4 inches deep to retain moisture and reduce surface evaporation
Water in the early morning or late evening for best absorption
Adjust watering frequency during heatwaves or dry spells
Newly planted trees need more frequent watering (every 2 - 3 days) until established, typically within the first 1 - 2 growing seasons.
Partner with Tree Experts for Long-Term Success
Watering is one of the most important, yet overlooked, aspects of tree care. Avoiding common mistakes and applying the right techniques ensures your trees stay strong and healthy, even in Idaho’s challenging summer conditions.
At Double J Tree Services, our certified arborists help homeowners in Boise, Meridian, Nampa, Caldwell, Kuna and the surrounding Treasure Valley understand the unique watering needs of different tree species and landscapes.