Flowers, shrubs and trees

OSU Extension helps Oregonians grow and care for flowers, shrubs and trees with research-based advice tailored to local climates and conditions. We provide guidance on plant selection, planting techniques and maintenance practices to support beautiful, healthy landscapes.

Featured resources

Caring for roses and dahlias in Oregon

Learn about planting, pruning and landscaping with these beautiful flowers.

Feb 2024 | Collection

Fire-resistant plants for home landscapes

Home landscaping is an important part of a community's resistance to wildfire. Learn what plants can help you create an attractive environment and reduce the risk of fire.

Amy Jo Detweiler, Stephen Fitzgerald, Ariel Cowan, Neil Bell, Thomas Stokely | Oct 2023 | OSU Extension Catalog Peer reviewed (Orange level)

Top 5 plants for unirrigated landscapes in Western Oregon

Drought-tolerant landscape plants for Western Oregon, including California lilac (Ceanothus), Rockrose (Cistus and Halimium), Manzanita (Arctostaphylos), Spider flower (Grevillea) and ground cover shrubs.

Heather Stoven, Neil Bell | Jul 2024 | Collection Peer reviewed (Gray level)

Become a Master Gardener!

The Master Gardener™ program educates Oregonians about the art and science of growing and caring for plants. This program also facilitates the training of a highly educated group of volunteers, who extend sustainable gardening information to their communities through education and outreach programs.

Learn more

Latest resources

Grow your own sunflowers

Grow bright, easy sunflowers in Oregon gardens. Learn how to plant, care for and harvest them, plus choose the best varieties for pollinators, cut flowers, wildlife, seeds and containers.

Brooke Edmunds, Shannon Rauter, Russell Smith-Ollivierre | Mar 2026 | OSU Extension Catalog Peer reviewed (Gray level)

Why is fungus growing on my lilac, and can the tree be saved?

Q: We have several older lilacs and have been gradually pruning them back over the past few years. One of the multi-trunked trees developed a fungus on one trunk, which we removed at the base. Is this lilac tree salvageable? ...

A: View answer | View all featured questions

Groundcover shrubs for Western Oregon gardens

The top 5 performing plants of groundcovers for Western Oregon landscapes.

Heather Stoven, Neil Bell | Feb 2026 | Educational gallery Peer reviewed (Gray level)

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Latest news

Native plants offer broader bee benefits than cultivars, OSU study finds

Research suggests wild-type varieties better support pollinator diversity.

Chris Branam | Apr 21, 2026 | News story

Add fall color to the landscape with vibrant, easy-care shrubs

While trees often steal the spotlight in fall, shrubs offer equally rich color and beauty.

Kym Pokorny | Oct 9, 2025 | News story

Plant spring-blooming bulbs in fall for years of low-maintenance color

Bulbs are naturally drought tolerant because they go dormant in summer and require no watering.

Kym Pokorny | Sep 11, 2025 | News story

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Flower resources

Growing wildflowers in Central Oregon

Learn how to grow wildflowers in Central Oregon, including choosing and preparing a site, planting and seeding rate, best times of year to do it, and application rate. Also includes a list of wildflowers that thrive in Central Oregon.

Amy Jo Detweiler | Mar 2024 | OSU Extension Catalog Peer reviewed (Gray level)

General care for hydrangeas

Look to this hydrangea how-to for advice on soil, water, pruning and more. Learn a simple pH trick that will turn blooms from pink to blue.

Kristin VanHoose | Jun 2024 | OSU Extension Catalog Peer reviewed (Gray level)

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Garden Future

What's the future of gardening in Oregon? Across Oregon, gardeners are seeing the seasons shift—hotter summers, wetter winters, unpredictable frosts. Together, we can adapt.Garden Future connects gardeners to share what’s working, learn from each other, and grow resilience in a changing climate. Garden Future is a project of the OSU Extension Master Gardener program.

Join the conversation

Photo: Artwork by Colby Brooks (Cropped from original)

Tree and shrub resources

How drought stress affects landscape trees

Drought creates stress on trees that isn't always obvious until it's too late. It's often difficult to connect the dots between a lack of water and a problem. Here's a look at how drought stress affects trees.

Nicole Sanchez | Feb 2024 | OSU Extension Catalog Peer reviewed (Gray level)

Fertilizing shade and ornamental trees

Learn how to identify signs of nutrient deficiency in shade and ornamental trees. Discover the most common soil nutrient deficiencies, types of fertilizer and fertilization techniques.

Ann Marie VanDerZanden | Jun 2024 | OSU Extension Catalog Peer reviewed (Orange level)

Beware of boxwood blight!

Useful information for homeowners, Master Gardeners and landscapers about boxwood blight disease: its symptoms, sanitation measures when it is discovered on a property, and preventive measures.

Cassie Bouska, Jay W. Pscheidt | Jun 2024 | OSU Extension Catalog Peer reviewed (Orange level)

Mulching woody ornamentals with organic materials

Using mulch around trees and shrubs has many benefits including improved soil quality and reduced water consumption. Learn about the types of mulch, how to use it and how to maintain its benefits.

Neil Bell, Dan M. Sullivan, Tom Cook | Apr 2024 | OSU Extension Catalog Peer reviewed (Orange level)

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Bees and pollinators

Garden soil and compost

Gardening techniques

Lawn and turfgrass

Integrated pest management

Nuisance wildlife

Upcoming Events

May 2

Plant & Garden Expo 2026

9:00 am - 4:00 pm Roseburg, OR

May 5

Central Oregon Master Gardener Spring Seminar Series: Hot Yards, Cool Tips - Firewise Landscaping

6:00 pm - 7:30 pm PDT Online

May 8 - May 9

34th Annual Polk Co. Master Gardener Plant Sale

9:00 am - 2:00 pm Rickreall, OR

May 9

Central Oregon Master Gardener Spring Seminar Series: Bouquets from the Garden

1:00 pm - 2:30 pm PDT Online

Meet Our Experts

Signe Danler

Home Horticulture Online Program Instructor

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

Amy Jo Detweiler

Horticulture

Brooke Edmunds

Community Horticulture, Master Gardeners

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

Jay W. Pscheidt

Professor and Statewide Extension Plant Pathology Specialist

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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Why is fungus growing on my lilac, and can the tree be saved?

A: View answer | View all featured questions

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