Summer in Ontario can bring long stretches of hot, sunny days. While we might enjoy the warmth, intense heat and dry conditions can be stressful for trees—especially young, newly planted, or already weakened ones. Without proper care, the summer heat can lead to water loss, leaf scorch, pest problems, and even long-term damage.
Whether you’re caring for a small ornamental tree in your backyard or a towering maple, here are some essential tips to help your trees thrive during the hottest months of the year.
1. Water Deeply and Consistently
One of the most important steps in summer tree care is proper watering. Hot weather accelerates evaporation, and trees can quickly become dehydrated.
- Water early or late: Water in the early morning or late evening to reduce evaporation loss and ensure the water penetrates the soil.
- Focus on the roots: Trees absorb water through their root system, so aim for deep watering rather than frequent light sprinklings. A slow soak encourages roots to grow deeper, which makes trees more resilient.
- Know your tree’s needs: Young trees typically need more frequent watering than mature ones—about 2–3 times a week during hot spells. Established trees may only need deep watering every 7–10 days, depending on the weather.
2. Use Mulch to Retain Moisture
Mulching is a simple yet highly effective way to protect trees from heat stress.
- Apply the right amount: Spread a 2–4 inch layer of organic mulch (wood chips, bark, or compost) around the base of the tree, keeping it a few inches away from the trunk to prevent rot.
- Benefits: Mulch helps keep the soil cool, reduces evaporation, and suppresses weeds that compete for water and nutrients.
- Natural insulation: Mulch acts like a protective blanket, buffering roots from extreme soil temperature changes.
3. Watch for Heat Stress Symptoms
Hot weather can trigger visible signs of stress in trees, such as:
- Wilting or drooping leaves
- Yellowing or browning leaf edges (leaf scorch)
- Early leaf drop
- Stunted growth
Catching these symptoms early can help you take action—like adjusting watering schedules or providing extra shade—to prevent long-term harm.
4. Protect Young and Vulnerable Trees
Young trees are more sensitive to high temperatures because their roots are still developing. To help them:
- Provide temporary shade: Use shade cloth or strategically place garden umbrellas during extreme heatwaves.
- Keep soil moist: Young trees have smaller root zones, so even short dry spells can affect them.
- Stake properly: If high winds are common in your area, staking young trees can prevent stress on their developing root systems.
5. Avoid Heavy Pruning in Peak Heat
Pruning is important for tree health, but in the peak of summer, removing too much foliage can expose branches to direct sunlight, increasing heat stress.
- Do light touch-ups only: Remove dead or damaged branches if needed, but save major pruning for late winter or early spring.
- Leave some canopy: The leaves provide shade for the trunk and help reduce water loss through transpiration.
6. Keep an Eye on Pests and Diseases
Hot, dry conditions can make trees more vulnerable to pests like spider mites, aphids, and borers. Fungal diseases can also spread if the weather turns humid.
- Inspect regularly: Check leaves, branches, and bark for signs of infestation or disease.
- Act promptly: Early treatment—whether through pruning, insecticidal soap, or professional pest management—can prevent serious damage.
- Promote tree health: Healthy trees naturally resist pests better, so consistent watering and mulching are your best defenses.
7. Consider Professional Tree Care
Sometimes, even with the best efforts, summer heat can overwhelm your trees—especially if they’re large, old, or already stressed. Professional arborists can:
- Diagnose heat-related damage and recommend targeted solutions
- Safely prune or remove hazardous branches
- Improve soil health with deep root fertilization
- Provide treatments for pests or diseases
Keep Your Trees Thriving All Summer Long
Summer tree care is all about balance—providing enough water, maintaining soil health, protecting against extreme heat, and avoiding unnecessary stress. By following these tips, you can help your trees stay strong, green, and beautiful all season long.
If you’re unsure about your tree’s condition or need expert help, Five Star Tree Services is here to assist. Our team of certified arborists can assess your trees, recommend a care plan, and carry out the work needed to keep them healthy. Contact us today to schedule your summer tree care service.