Managing Summer Heat Stress in Trees & Shrubs

How to Protect Your Landscape When the Temperatures Rise

Introduction

By June in Northwest Indiana, we start to feel the shift toward summer—hotter days, drier conditions, and more stress on your landscape. Trees and shrubs need extra care this time of year, especially newly planted or ornamental varieties.

Here’s how to help your landscape stay healthy and resilient through summer heat.

1️⃣ Watch for Signs of Heat & Drought Stress

Heat-stressed trees and shrubs often show signs before damage becomes irreversible. Be on the lookout for:

• Wilting, curling, or scorched leaves

• Premature leaf drop

• Browning at leaf margins

• Slower growth or stalled bud development

• Drooping branches, even after rain

These symptoms may appear suddenly during hot, dry spells.

2️⃣ Watering: Deep, Infrequent, and Targeted

Inconsistent or shallow watering is one of the biggest stressors for trees. Use these guidelines:

• Water early in the morning to reduce evaporation

• Focus on the root zone, not the leaves

• Apply water slowly to allow deep penetration (aim for 6–12 inches)

• Use drip irrigation or soaker hoses when possible

• Water less frequently but more deeply (once or twice a week in dry periods)

💧 Young and newly planted trees are most vulnerable and may need watering through their first 2–3 summers.

3️⃣ Mulch Management for Moisture & Temperature Control

Proper mulching can reduce soil temperature and moisture loss dramatically.

✔ Maintain a 2–3 inch layer of mulch around trees and shrubs ✔ Keep mulch several inches away from trunks and stems ✔ Refresh mulch in early summer if it’s broken down or scattered ✔ Use shredded bark, wood chips, or composted mulch—avoid dyed products

4️⃣ Avoid Heavy Pruning or Fertilizing in Mid-Summer

Pruning and fertilizing can stimulate new growth that’s more susceptible to heat damage.

✂️ Save major pruning for fall or next spring unless it’s for safety or damage. 🌱 Hold off on fertilization unless a deficiency is confirmed by testing.

🌿 Final Thoughts

Summer stress is manageable when you’re proactive. With proper watering, mulch care, and monitoring, your trees and shrubs can weather the heat and stay strong through the growing season.

📞 Need help identifying heat stress or planning a summer maintenance strategy? We’re here to help.