Trees feel stress, too!

What do humans and trees have in common? More than you might think. We both rely on water and nutrients, and we both need ways to stay cool. Trees function a lot like we do.

And there’s one big thing we both need to avoid: stressed trees.

We all know how stress affects the human body over time—fatigue, headaches, trouble sleeping, and a weakened immune system. Trees deal with stress too. When stress builds up, it makes trees more vulnerable to pests, disease, and long-term decline.

Many factors can stress trees, especially in urban and residential environments. Here are some of the most common stressors:

Air Pollution

Dust and particulates can block leaf pores and reduce photosynthesis. Trees also “sweat” through a process called transpiration, which helps them cool down. When particulates clog leaf surfaces, trees can overheat.

Ozone and acid rain can damage bark and disrupt soil pH. Stressed trees may also release volatile carbon compounds, which can contribute to air pollution.

Excessive Pruning

Over-pruning triggers stress quickly. It creates several problems at once:

• Removing too many limbs creates large wounds

• Removing too many leaves cuts off the tree’s energy supply

• Sudden sun exposure can damage bark and tissue

Poor Soil Conditions

Construction, vehicles, and heavy foot traffic compact soil and limit oxygen access for tree roots. Compacted soil also reduces nutrient absorption. Poor-quality topsoil (common in new housing developments) can also stress trees over time.

Healthy soil matters—and compost helps.

Temperature Stress

Cities and developed neighborhoods create “heat islands.” Concrete and metal absorb and hold heat differently than turf. That extra heat raises temperatures and increases tree stress, especially in summer.

Light Pollution

Trees rely on natural light cycles. Constant artificial light can disrupt growth patterns and seasonal responses. Imagine trying to sleep with the lights on every night.

Storm Damage

Storms can break branches, tear bark, and expose trees to decay. You can’t prevent storms, but you can protect your tree after damage. Clean, correct pruning cuts help the tree heal and reduce the risk of rot.

Moisture Problems (Too Much or Too Little)

Water stress causes major problems for trees. Trees consist of about 75% water, and leaves can reach up to 99% water.

Trees need water to move nutrients from the roots to the canopy. During peak spring growth, a mature red oak can use 100–200 gallons of water per day.

More resources on watering trees:
University of Nebraska Extension: https://nfs.unl.edu/when-water-trees/
University of Nebraska Extension: https://lancaster.unl.edu/5-common-questions-about-trees-drought-and-fall-watering/

Missing Essential Nutrients

Trees need a healthy balance of essential elements like:

• Carbon dioxide (CO₂)

• Water (H₂O)

• Nitrogen (N)

• Phosphorus (P)

• Potassium (K)

Soil pH plays a major role in nutrient availability. A professional soil test can identify issues before symptoms become severe.