Tree Care and Maintenance

Seasonal Tree Care Tips: Winter
Start Smart: What to Consider Before Planting a New Tree

The best time to plant trees in Western Oregon is considered to be November through April. The best time to ensure a healthy, long-lived tree is before you buy it. Choosing a tree at the nursery is less about how it looks today and more about how it will function decades from now. Thoughtful selection begins before planting and considers the tree’s role, environment, and structure.

Start by identifying the tree’s function and form. On urban lots, trees often provide shade, privacy, or seasonal interest while sharing space with buildings, sidewalks, and utilities. What purpose will the tree serve? Do you want shade, privacy, seasonal color, ornamental value, or wildlife habitat? The natural shape and mature height and width should match its purpose and the available planting space. Many common landscape trees grow larger than people anticipate. Choose a species with a growth habit that naturally fits the site to minimize the need for future crown pruning and conflicts like sidewalk uplift or interference with overhead utility lines.

Next, choose a species suited to your hardiness zone and local conditions. Most urban areas in the Willamette Valley fall within USDA Hardiness Zones 8b (Sunset Zone 6), but microclimates created by buildings and streets can intensify heat or frost.

Then, match the species to your site conditions. Soil type, drainage, and exposure matter as much as climate. Poorly drained clay soils or compacted urban soils can suffocate roots, while excessively dry soils can cause drought stress. Sun and wind exposure also matter; a tree that prefers partial shade may struggle in full sun or strong winds. Favor species with good resistance to common insects and diseases; planting a mix of species reduces the risk of widespread loss from pests or disease outbreaks.

Finally, one you have decided on a species, be sure to inspect the quality of the available nursery stock. Look for a tree with good symmetry, well-distributed branches around the trunk, a single well-developed leader, plump and healthy buds, a reasonably straight trunk with no bark wounds, and healthy roots. Yes, you should inspect the root system before buying! A healthy tree should have a visible root flare at the base of the trunk and avoid trees with circling or girdling roots. Strong root architecture sets the foundation for stability, nutrient uptake, and long-term stability. Smart selection at the nursery helps urban trees establish faster, require less maintenance, and deliver benefits for decades.

Here is a quick checklist for selecting a tree at the nursery:

☐ Does the tree’s purpose match its natural form and growth habit?

☐ Will its mature height and width fit the space without conflicts?

☐ Is it appropriate for USDA Zones 8–9 and urban microclimates?

☐ Is the tree suited to your soil type and drainage?

☐ Will it tolerate the site’s sun and wind exposure?

☐ Does it have good resistance to local insects and diseases?

☐ Are the roots healthy, with a visible root flare and no circling or girdling roots?

Learn more about what to consider before planting a new tree by visiting these sites:

• Selecting, Planting and Caring for a New Tree
• How Do I Choose a Nursery Tree?
• How to Select and Plant a Tree

 Please check back for more seasonal tree care and maintenance advice!

Link to Tree Care and Maintenance Archives
 

Archives

Fall 2025: Invasive Plants

Summer 2025: Heat Stress and Sunscald

Spring 2025: Trees for Bees…and Other Pollinators, Too

Winter 2025: Fruit Tree Maintenance

Fall 2024: For a Healthier Yard, Leave the Leaves

Summer 2024: Tree Risk Assessment

Spring 2024: Invasive Ivy Removal

Winter 2024: Clean and Sharp Pruners

Fall 2023: Mediterranean Oak Borer

Summer 2023: Supplemental Watering and Mulch to Prevent Drought Stress in Trees

Spring 2023: Aphids

Winter 2023: Pruning: Standards and Best Practices

Summer/Fall 2023: Emerald Ash Borer

Winter/Spring 2022: Nesting Season

Fall 2021: Healthy Trees are Defended Trees

Special Edition: After the Storm

Winter 2021: What is an Arborist?

Fall 2020: Soil Management  

Summer 2020: Retaining and Creating Snags for Wildlife

Spring 2020: Mulch: Numerous Benefits and Easy Application

Winter 2020: Tree Planting: To Stake or Not to Stake?

Fall 2019: Insects and Diseases

​Summer 2019: Drought Stress Revisited

Spring 2019: Trees and Construction

Winter 2019: Topped Tree

Fall 2018: Autumn Leaves

Summer 2018: Emerald Ash Borer

Spring 2018: Pruning Young Trees

Winter 2017: Tree Related Storm Damage

Fall 2017: New Tree Selection and Planting

Summer 2017: Trees and Turfgrasses

Spring 2017: English Ivy Removal

Winter 2017: Recognizing Tree Risk

Summer 2016: Drought Stress

Fall 2016: Preparing Trees for Winter

Additional Tree Care Resources:
 

Right Tree in the Right Place

Use this handy guide for assistance in choosing the right species of tree based on the constraints of a site, such as overhead wires, narrow plant strips, and proximity to structures.

"Right Tree Right Place" - helpful information such as "Use this guide for assistance in choosing the right species of tree based on the constraints of a site, such as overhead wires, narrow plant strips, and proximity to structures."

"Master Plant List" - a guide to the plants that are acceptable for mitigation requirements in Lake Oswego.

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