How to Identify Heat Stress in Evergreens
Evergreens are known for their resilience. With waxy needles and deep root systems, they’re built to withstand harsh winters and summer heat alike. But when Midwest summers bring extended periods of high temperatures and little rainfall, even the toughest trees can show signs of stress.
The challenge? Unlike deciduous trees, evergreens often hide their symptoms until the damage is done. That’s why early detection is key—especially for landscapers and nursery professionals who want to ensure healthy plantings and avoid costly replacements.
Spring foliage emerging from evergreens are tender and therefore susceptible to damage from excessive heat and drought.
What to Watch For:
One of the earliest and most overlooked signs of heat or drought stress is a slight dulling of needle color. Needles may appear grayish or washed out, especially on the newer growth. This subtle “graying out” is often the first indication that the tree is struggling to keep up with moisture loss.
Other signs include:
Wilting or curling needles
Browning at needle tips
Thinning foliage, especially toward the interior of the tree
Delayed or stunted new growth
Why It Happens:
While the heat itself isn't always the issue, the drought conditions that often come with it are. Evergreen needles are designed to conserve water—but prolonged drought can still lead to dehydration. In containers and balled-and-burlap (B&B) trees, the risk is even greater. Limited root space means these trees dry out faster, and if not watered deeply and regularly, stress will follow.
A water droplet falls from an evergreen needle.
What You Can Do:
Check Soil Moisture: Stick a finger or soil probe a few inches into the root ball—if it’s dry, water thoroughly.
Water Deeply and Consistently: Avoid shallow watering. Saturate the root zone to encourage deep root growth.
Mulch Around the Base: A layer of mulch helps regulate soil temperature and retain moisture. This is especially helpful for B&B trees in holding areas before moving to jobsites.
Inspect Frequently: Especially during dry spells, walk your rows regularly to spot changes early. Prepare supplemental irrigation prior to anticipated drought conditions.
Built for Midwest Summers:
At Armintrout’s, we grow evergreens in well-drained soil and ensure they’re fully acclimated to Michigan’s conditions before they reach your job site. Whether you're installing container-grown or B&B trees, you can trust they’ve been field-tested for resilience.