Urban forestry

OSU Extension supports healthy urban forests by providing research-based information on tree selection, planting and care in city and neighborhood settings. We work with communities, professionals and volunteers to enhance green spaces and promote long-term tree health and resilience with a focus on wildland urban interface.

Protecting trees on construction and development sites

Learn best practices for protecting, conserving, maintaining and replacing trees during development in the Pacific Northwest, ensuring urban forest health amid construction activities.

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Photo Credit: Setae - Adobe Stock (Cropped from original)

Latest Resources

Should we give away our tree seedlings?

I have many Douglas fir seedlings that sprout up on my property and I hate to pull them out. I also have a few that are a foot or two tall now. Would it be beneficial to anyone if I donated the seedlings/trees? I have maybe 12–24 or more per year, and so do my neighbors.

Norma Kline | Dec 2025 | Featured question

Should I top tall, slender oak trees next to my house?

Near our house and deck we have some tall slender oak trees. I’m concerned about the safety of the house, especially during wind storms. Will topping the trees affect their life?

Jennifer Killian | Oct 2025 | Featured question

What’s causing leaf damage to oak trees?

Our oak tree is about 70 feet tall. This spring, it developed dried-out bunches of leaves starting at the ends of the branches. It's rapidly getting worse, with more branches looking like they're dying. What’s going on? Can it be stopped? I’m noticing many oaks have this issue.

Lorelle Sherman | Jul 2025 | Featured question

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Featured resources

Recognizing ash trees in Oregon, Washington and Northern California

How to identify our native and common landscaping ash trees, including look-alikes. All ash trees are susceptible to emerald ash borer, an invasive pest first sighted in Oregon in June 2022.

David C. Shaw | Jul 2022 | Educational gallery Peer reviewed (Gray level)

Ecological design of urban landscapes: Economic, social and ecological benefits

An ecological approach to landscape design incorporates natural systems as an integral part of urban landscapes. Learn how to bring ecology and design together to form a sustainable urban landscape.

Signe Danler, Gail Langellotto | Oct 2024 | OSU Extension Catalog Peer reviewed (Orange level)

Fire FAQs — Are Structures Fuel? The Wildland Urban Interface and the 'Built' Environment

We now need to consider structures themselves as a fuel type contributing to wildfires, along with other potentially hazardous fuel such as wood piles, propane tanks and automobiles. In this context, the home ...

Dan Leavell, Stephen Fitzgerald, Carrie Berger, Gavin Horn | Jun 2023 | OSU Extension Catalog Peer reviewed (Orange level)

Shrubs to Know in Oregon and Washington

This photo-packed field guide makes shrub identification easy and fun. It features 100 of the most common shrubs that grow in and around Pacific Northwest forests — from southern British Columbia to Northern California and from the Pacific Ocean to the northern Rockies. You'll find individual range maps and complete descriptions for each species as well as notes on range, habitat and plant names.

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Credit: Oregon State University (Cropped from original)

Pruning videos

Pruning with the Pros - Introduction

In an ideal world, trees have been well pruned since planting, and only occasional maintenance pruning is needed. In reality, we often inherit mature trees in need of corrective pruning in order to serve their best function ...

Feb 2022 | Video

Pruning with the Pros - Tools of the Trade

A selection of tools that are needed for proper tree pruning in the landscape. With Oregon State University Extension’s Nicole Sanchez and certified arborists John Bellon and Tom Ford.

Feb 2022 | Video

Pruning with the Pros - Is this tree worth saving?

What a “volunteer” tree is in a landscape, its merits, and how it can be salvaged for a more attractive profile. With Oregon State University Extension’s Nicole Sanchez and certified arborists John Bellon and Tom Ford.

Feb 2022 | Video

Pruning with the Pros - When to get professional help

Some tree pruning issues that require professional help, and a demonstration of how a professional assesses a tree’s structure.

Feb 2022 | Video

Trees to Tap: How Forest Practices Affect Oregon's Municipal Water

Forests produce economic benefits such as timber, forest products and jobs. They also provide wildlife habitat, recreation, carbon storage and clean water. In fact, most of Oregon’s drinking water is sourced from our forests. But logging, forest road building, using herbicides and other activities related to growing and harvesting timber can impact the quality and quantity of water. Oregon State University scientists examine these links in this comprehensive look at watershed health.

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Tree care

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Upcoming Events

Feb 3

Stepwise journey of tree identification*

7:00 pm - 8:00 pm PST Online

Feb 7

Propagating Native Plants: A Gardener's Guide

10:00 am - 12:00 pm Eugene, OR

Meet Our Experts

Jennifer Killian

Urban Forestry Specialist

Sarah C. Low

Urban Forestry Specialist

Signe Danler

Home Horticulture Online Program Instructor

Contact for questions about Home Horticulture online. Submit other questions to Ask Extension, link below.

Brooke Edmunds

Community Horticulture, Master Gardeners

Contact me about the Master Gardener Program or gardening questions from Marion or Polk counties

Have a question? Ask Extension!

Ask Extension is a way for you to get answers from the Oregon State University Extension Service. We have experts in family and health, community development, food and agriculture, coastal issues, forestry, programs for young people, and gardening.

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Should I top tall, slender oak trees next to my house?

Q: Near our house and deck we have some tall slender oak trees. I’m concerned about the safety of the house, especially during wind storms. Will topping the trees affect their life?

A: View answer | View all featured questions

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