How to Care for Trees During Hot Weather

In this article

(Portland, Oregon) -

As the temperature remains high this summer, it is crucial for our community to come together and ensure the well-being of the city's trees. Portland's trees are more than scenery - they are part of who we are. They live along our streets and in our parks and yards. They shade our children on their way to school and inspire joy, rest, and play.

Trees are an investment and giving them proper maintenance and care will ensure their longevity. Portland Parks & Recreation (PP&R)'s Urban Forestry team is pleased to provide valuable insights on how to care for trees during scorching hot summer days.

Hydration is Key: Just like human beings, trees need water to survive the summer heat. During extended periods of high temperatures, it's important to water trees adequately. Provide a deep, slow watering at the base of the tree to ensure moisture reaches the roots. Water in the early morning or late evening to minimize evaporation. Young trees benefit from weekly deep watering during hot weather, while established trees generally only need supplemental watering every two to four weeks during prolonged dry periods.

Mulching Matters: Applying a layer of organic mulch around the base of trees can greatly benefit them during hot weather. Mulch helps retain soil moisture, suppress weeds, and regulates soil temperature. Make sure the mulch is spread evenly to a depth of three inches but keep it three inches away from the tree trunk.

Pruning Wisely: Prune trees to remove poorly connected branches and to train the tree for street and sidewalk clearances. Pruning allows trees to focus their energy on healthy growth. Wait two or three years to prune newly planted trees. However, during heat waves, avoid extensive pruning as it can stress the tree further.

Protect the Trunk from Sunscald: Young and newly planted trees are more susceptible to sunscald and heat stress on the trunk, especially during periods of intense afternoon sun. Use a shade cloth or burlap to create a temporary shade structure that reduces sun exposure to the trunk. Remove the shade structure when extreme heat is over.

Watch for Signs of Stress: Heat stress in trees can appear in ways such as wilting, yellowing leaves, or premature leaf drop. If you notice these signs, act immediately by providing extra water and care.

Know Your Trees: Different tree species have varying tolerance levels to heat and drought. Understanding the specific needs of the trees in your area can help you tailor an effective care routine.

By taking these simple yet effective steps, we can ensure the health and longevity of the urban forest even in the face of extreme weather conditions.

Trees are part of the very fabric of our city

Like our water, sewer, and transportation systems, Portland's trees are essential infrastructure. They clean our air and water, cool our neighborhoods, support our health, give homes to wildlife, and help our city handle flooding and climate change. PP&R regularly plants new trees in areas of town where the canopy is lower.

For more information on tree planting and care throughout the year, visit portland.gov/trees/tree-care.

About PP&R's Urban Forestry Division

PP&R Urban Forestry staff care for our vibrant and diverse urban forest - the 1.2 million trees in parks and natural areas, 333,000 street trees, and 2.9 million trees on private property.

Valued at $9.5 billion, Portland's trees are critical city infrastructure. Urban Forestry protects and grows this shared asset through tree planting and care, education, volunteer stewardship, and community partnerships - with research, data, and community feedback guiding our programs and services. Our work is informed by the Portland Urban Forest Plan, which provides a roadmap for protecting, expanding, and caring for Portland's trees. We are proud of our long history protecting this vital asset, reflected in the City's nearly 50-year recognition as a Tree City USA, our designation as a Tree City of the World, and our accreditation for urban forestry excellence by the Urban and Community Forestry Society.

Portland Clean Energy Community Benefits Fund and Parks Local Option Levy

These key funding sources provide Portlanders with better and more equitable tree care across the city. The Portland Clean Energy Community Benefits Fund (PCEF) provides PP&R Urban Forestry funding to plant at least 15,000 new trees over five years, reduce tree care costs for Portlanders, expand community education, and open doors to new careers in the tree-care industry. PCEF invests in community-led projects to reduce carbon emissions, create economic opportunities, and help make our city more resilient as we face a changing climate.

With funding from the 2025 Parks Levy, PP&R is working to restore natural areas, plant more trees, safeguard clean water, protect wildlife, diminish the effects of climate change, and provide appropriate care for the 1.2 million trees in Portland's parks. The Levy is also funding the Portland Urban Forest Plan and related work.