The Right (and Wrong) Way to Water Trees During a Calgary Heatwave

Calgary summers aren’t just hot; they’re bone-dry. Our rollercoaster weather swings from cool mornings to blazing afternoons, and these wild swings take a real toll on your trees, making proper watering even more critical.

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So, how much water do your trees need? In this quick guide, we’ll tell you exactly how to water your green giants on those intense summer days. 

The Right Way to Water During a Heatwave

When the heat hits, it’s tempting to grab the hose every day. But with trees, frequent watering isn’t better. It’s depth that matters.

1. Water Deeply, Infrequently

Focus on long, slow soakings once or twice a week. Use enough water to saturate the soil 12 to 18 inches deep, this is where most feeder roots live. 

Deep watering builds drought-resilient root systems and keeps trees from panicking when temperatures spike.

2. Water Early Morning

The best time to water is early morning when temperatures are cooler and winds are calmer. Less evaporation means more water reaches the roots. Afternoon watering can actually raise soil temperatures, while evening watering leaves foliage damp overnight, inviting disease.

3. Use the Right Tools

Soaker hoses or drip irrigation systems deliver water slowly and evenly, letting it soak deep into the soil. Avoid spray nozzles and sprinklers during heatwaves. They wet the surface but fail to penetrate where it matters most. 

If you’re hand-watering, apply water slowly at the base, moving around the dripline to cover the full root zone.

4. Mulch (But Do It Right)

Mulch is one of the best tools to combat heat stress. Apply 2–4 inches of mulch around the root zone to regulate soil temperature, reduce evaporation, and suppress weeds that compete for moisture. But avoid “mulch volcanoes”. Keep mulch several inches away from the trunk to prevent rot and insect problems.

5. Adjust Based on Tree Type

Newly planted or young trees need more frequent monitoring since their roots aren’t yet established. You may need to water these trees two to three times per week during extreme heat. Mature, established trees can tolerate longer intervals between deep soakings, but still need attention if the heatwave drags on.

6. Watch the Soil

Before watering, check the soil moisture. Stick a screwdriver or soil probe into the ground. If it goes in easily and feels moist 8–12 inches down, you can hold off. If it’s dry and crumbly, it’s time to water.

Get Tree Care Advice from Your Local Arborists

Even with proper watering, some trees buckle under the intense heat. Watch for these early warning signs of heat stress:

• Wilted or drooping leaves
• Browning or scorched leaf edges
• Leaves dropping early (premature defoliation)
• Dry, brittle branches
• New growth that’s smaller or stunted
• Cracking or splitting bark

The sooner you act, the better chance your tree has to recover. Our team of 23 ISA-certified arborists can assess your trees, and create a tree health care plan tailored to your yard and tree species.

Don’t wait until the damage is irreversible. Book your free assessment today and let Green Drop Trees help your trees thrive, even in the toughest Calgary summers.