Trees play a vital role in our landscapes, offering shade, improving air quality and enhancing aesthetics. During the scorching summer months, however, the extreme heat can harm even the hardiest trees. Understanding these risks and how to address them can ensure your trees thrive year after year. Below are 10 surprising ways summer heat can damage your trees and actionable tips to protect them.
1. Dehydration
Hot temperatures and long summer days can dry out the soil and leave your trees gasping for moisture. When trees lack water, they struggle to transport nutrients, weakening their overall health.
Solution
Deeply water your trees early in the morning or late in the evening to prevent evaporation. Use mulch around the base to retain moisture and regulate soil temperature. Aim for a slow soak that reaches the roots, rather than a quick surface spray.
2. Sunscald
Young or thin-barked trees are particularly vulnerable to sunscald, an injury caused by the sun heating the bark to damaging levels. This can lead to cracks, dead bark and even infections.
Solution
Wrap the trunks of young trees with tree guards or reflective wraps to shield them from the sun. Another option is applying a diluted latex paint mixture to the trunk, which acts as a natural sunscreen.
3. Root Damage from Overheated Soil
The ground can absorb and retain heat, especially in areas with poor shading or heat-reflective surfaces nearby. Prolonged exposure to this heat can stress and damage tree roots, compromising water absorption.
Solution
Add a 2–4 inch layer of organic mulch around the base of the tree to insulate the roots and keep the soil cooler. Be sure to leave a gap around the trunk to prevent rot.
4. Leaf Scorch
Leaf scorch causes leaves to brown on the edges and curl, signaling severe water loss or salt buildup. While this is most common in younger or newly planted trees, mature trees can suffer, too.
Solution
Ensure your tree is getting consistent watering. Use a drip irrigation system to maintain steady hydration levels. Consider adding compost to the soil to improve water retention and reduce salt buildup.
5. Stunted Growth
Excessive summer heat can lead to stress, diverting the tree’s energy away from growing to simply surviving. This results in weaker, slower growth and fewer leaves or fruits.
Solution
Help support growth by fertilizing before the summer heat intensifies. Choose a slow-release fertilizer that provides steady nutrients and avoid over-pruning during hot months, which can stress the tree further.
6. Pest Infestations
Summer heat creates a perfect environment for pests like mites, borers and aphids to thrive. Stressed trees are especially vulnerable and may experience invasive infestations.
Solution
Inspect your trees regularly for signs of pests, such as holes in leaves, sticky residue or odd growths. Use natural pest repellents or consult an arborist to recommend safe treatments. Keeping your trees healthy and stress-free is the best defense.
7. Branch Breakage
Dry, brittle branches are more likely to snap under their own weight or from a summer storm. Poor hydration and heat stress often aggravate this issue.
Solution
Prune weak or damaged branches in spring, before the heat intensifies. During summer, avoid heavy pruning and monitor trees after storms, pruning only when needed to address hazards.
8. Disease Outbreaks
Hot, humid environments can encourage bacterial and fungal diseases, such as powdery mildew or leaf spot. Trees weakened by heat stress are prime targets.
Solution
Promote good airflow by pruning dense areas of foliage in early spring. Water at the base, rather than overhead, to reduce moisture buildup on leaves. If disease develops, treat quickly with appropriate fungicides or bactericides.
9. Loss of Nutrients
Intense heat and dry conditions can make it harder for trees to absorb nutrients from the soil. This nutrient deficiency may lead to yellowing leaves and poor fruit or flower production.
Solution
Apply slow-release fertilizers and test your soil to ensure it has the proper nutrients. Adding organic matter, like compost, can boost nutrient levels while improving soil structure and moisture retention.
10. Embedded Heat Stress
Over time, cumulative heat stress can shorten a tree’s lifespan. This includes internal damage to tissues and structures, making trees increasingly vulnerable to external threats.
Solution
Focus on overall, year-round care. Implement regular deep watering, seasonal pruning, pest monitoring and soil enrichment. Shade-sensitive species may benefit from strategic placement near larger trees, buildings, or canopies.
Protecting Your Trees Starts Today
Don’t wait to notice signs of damage before taking action. Proactively caring for your trees during summer ensures their long-term health and beauty.
In addition to these tips for properly caring for your trees this summer, we at Excel Tree Care offer additional services to help you maintain safe, beautiful and healthy landscapes. Need expert help? Call Excel Tree Care at (404) 964-6508 for a free estimate or immediate assistance. Our fully licensed and insured team is ready to help you with all your summer tree care needs!