Which Growing Zones are in Oregon?

From the verdant coastal forests of the West Coast to the dry, high desert mountains of the Eastern Cascades, Oregon is a remarkably diverse state known for its rich agricultural lands. The state is divided in two by the Cascade Mountain Range, with the bulk of the growing action happening on the western side. The state includes five major growing zones and 11 half-zones.

Wine grapes, fruit trees, and hundreds of varieties of vegetables thrive in western Oregon’s moist, mild winters and hot, dry summers. Hazelnuts, peppermint, cherries, blackberries, pears, and carrot seeds are other major specialty crops. The mountainous and eastern parts of the state are much colder and drier but still suitable for most vegetables and herbs, particularly potatoes, mint, and onions. 

Most notably for landscapers and gardeners, Oregon is home to a thriving nursery industry producing thousands of species of landscape shrubs and ornamentals for home use. No matter where you reside in the Pacific Northwest, it’s helpful to understand your growing zone so you can choose the right plants for your garden. This map provides a visual representation of Oregon’s varying zones.

In addition to many years of farming experience across the Beaver State, I used to work for Oregon State University’s agricultural extension service, helping local growers produce the highest quality crops possible. Let’s dig into the nuances of Oregon’s major growing zones and how you can make the most of your microclimate for gardening.

What Growing Zones are in Oregon?

Known for its lush Pacific Northwest forests, snow-capped mountains, and green agricultural valleys, Oregon is remarkably diverse. The state’s 98,000 square miles encompass zones 5a through 10a. With an abundance of winter rains and warm, dry summers, most of the state is a gardener’s dream. You can plant everything from exotic kiwi fruit to Mediterranean olives to outrageously delicious blackberries and the state’s iconic Marionberries. 

Growing zones are determined by the average extreme annual temperature highs and lows based on decades of climate data. The USDA Plant Hardiness Zone Map is determined by the United States Department of Agriculture’s Agricultural Research Service in conjunction with Oregon State University. Oregon’s prominence in the agricultural and gardening world expands far beyond the state’s border. OSU is one of the leading agricultural schools (and my alma mater!), making their climatic research essential for delineating growing zones throughout the entire U.S. 

Recent updates to the USDA growing zones have shifted much of Oregon into warmer zones. Rising average temperatures have directly impacted crop production in the Pacific Northwest, particularly in southwestern Oregon coastal regions where subtropical plants can now be grown. Grape-growing regions are shifting progressively northward and higher in elevation as summer temperatures warm, and Mediterranean crops like olives can now grow in many areas of Oregon.

Here is more detail on each growing zone and what you should know about your specific part of the Beaver State.

Zone 5

The coldest regions of the state are found in high-elevation areas of eastern Oregon throughout the Cascades, including the Blue Mountain and Wallowa Mountain Ranges. Frigid zone 5a has an average extreme low of -20°F (-29°C), while the extreme lows of zone 5b hover around -10°F to -15°F (-23°C to -26°C). The summers in these areas can be fairly mild and are still amenable to a range of fruit, vegetable, and ornamental plants.

Zone 5 is mostly constrained to small mountainous areas with a lot of snowpack. Native trees and shrubs are particularly suitable here because they are accustomed to dry summers and wet winters. Apples are the most popular fruiting trees in central Oregon. You can also grow hardy Asian pears, plums, sour cherries, and hazelnuts. 

Tender perennials like chrysanthemum, lavender, wallflower, and various bulbs appreciate deep mulch to help them survive winter. Classic herbaceous plants like thyme, yarrow, valerian, soapwort, stonecrop, and salvia have no problem thriving in this zone. They may die back to the ground in winter yet reliably return in the spring.

Zone 5 has a medium length frost-free growing season, so vegetable gardeners are encouraged to give their seeds a head-start indoors. With an average last frost around mid-May and the first autumn frosts around mid-October, you can grow most all warm-weather crops, including tomatoes, peppers, melons, and squash. A greenhouse or low tunnel is helpful for keeping plants cool on warm nights. Many central Oregon growers rely heavily on thick floating row fabric to keep their crops cozy during the unpredictable buffer seasons.

Zone 6

The largest areas of Central Oregon reside in zone 6, including Bend, Klamath Falls, and Pendleton. Most everywhere east of the Cascade Mountains falls in this zone. Zone 6a has extreme lows of -5°F to -10°F (-21°C to -23°C), and zone 6b ranges from 0°F to -5°F (-18°C to -21°C). These areas are known for extra hot, dry summers that are, unfortunately, highly prone to wildfires. A firewise landscape is essential to keep your home and structures safe from flames. 

Defensible space ensures no flammable plants are growing within 30 feet of buildings or decks. Firewise landscape design commonly begins with native deciduous trees like bigleaf maple, white alder, live oak, and wild plum. Deciduous trees tend to be less flammable because they have tall central trunks, a higher moisture content, and thick bark. However, it is still important to rake leaves and remove low twiggy growth regularly.

Waterwise plant selections are also important in zone 6 because it receives less rain than Western Oregon. Drought-tolerant native plants like vine maple, serviceberry, yarrow, heartleaf bergenia, hummingbird mint, ornamental alliums, and butterfly weed are very popular for their beauty and low maintenance. 

Vegetable gardeners should also consider water usage in annual beds. A buried olla (clay pot waterer) can be helpful for drought-prone areas of zone 6. Soaker hoses, drip irrigation, and thick layers of mulch are helpful for conserving water and preventing foliar diseases. 

The frost-free growing season from April to November ensures ample time for a huge diversity of vegetables and fruits. Make the most of your garden season by practicing succession planting, which uses staggered planting dates to enjoy prolonged harvests.

Zone 7

The foothills of the Cascades and the Hood River Valley are considered growing zone 7. These regions still have snowy, wet winters and hot, dry summers, but they are milder than Central Oregon. Zone 7 is particularly well known for its orchards, producing an abundance of the state’s apples, pears, cherries, plums, strawberries, and blackberries. 

Cherries are particularly popular in this region, and you can grow incredible ‘Bing’ or ‘Rainier’ cherries anywhere in Oregon’s zone 7. The main cherry harvest window is July and August, but gardeners at higher elevations may enjoy fruit into late summer.

The average extremes in zone 7a dip to 0°F to 5°F (-18°C to -15°C), while zone 7b ranges from 5°F to 10°F (-15°C to -12°C), allowing a range of perennials to thrive here. Sunny zone 7 borders are perfect for dogwoods, Indian plum, huckleberries, ninebark, and flowering currants, while shadier forested areas excel with azaleas, rhododendrons, woodland strawberries, and hostas. Native Oregon wildflowers like Pacific bleeding heart and camas are extra special additions to a zone 7 landscape.

With frost-free days from April to November, the seven-month (or longer) growing season ensures vegetable gardeners also have ample time to enjoy as many tomatoes, zucchini, peppers, and warm-weather crops as possible. 

Zone 8

Oregon’s richest agricultural growing zones are in zone 8. This zone includes most of the Willamette Valley, from Portland south to Salem, Corvallis, Eugene, and Medford. The average extreme lows are 10°F to 20°F (-12°C to -7°C).

Hazelnuts, berry shrubs, and vines are also particularly suited to this area. The Willamette Valley is a major producer of strawberries, blackberries, blueberries, boysenberries, and marionberries. You can easily incorporate these plants into espalier borders or containers.

Marionberries are a unique hybrid type of blackberry exclusive to Oregon. Developed by Dr. George Waldo in Corvallis in 1948, they are richer, firmer, and more complexly flavored than regular blackberries. The mix of tartness and sweetness makes these berries a regional delicacy. Plant canes four to five feet apart with a sturdy trellis, as the vines can reach 16-20 feet.

Zone 8 is also a prime region for vegetable growing. I worked on many diversified organic vegetable farms throughout this area and was consistently amazed by the possibilities for specialty produce. Thanks to the long frost-free growing season and abundant winter moisture, thousands of varieties of vegetables are suitable for zone 8 gardens. Oregon’s foodie and chef culture goes hand in hand with the innovative small farms and seed growers, offering a thriving local food scene of garden clubs, farmer’s markets, and community growing spaces.

However, the main growing challenge in the valley is the winter and spring moisture. The heavy clay soils are prone to waterlogging and require generous amendment with organic matter to ensure adequate drainage. Powdery mildew and Botrytis are also common plant diseases that affect plants during the rainy, cloudy months. You may need to space plants wider and prune more often to maintain proper airflow. 

Zone 9

Oregon’s growing zone 9 includes inner-city urban Portland and most of the Oregon Coast. These areas are so mild that they barely frost. The extreme annual temperatures rarely dip to 25-30°F (-4 to -1°C). Gardeners in zone 9 have an abundance of plant options at their fingertips and don’t have to worry about the extreme cold or heat faced by inland growers. However, coastal regions have their own unique challenges, such as excessive humidity and extremely cloudy winters. The Pacific Northwest gloom isn’t only problematic for mental health, but it also makes it difficult for some plants to grow because the hours of daylight are so short.

The Oregon coast is particularly suited to native perennial plants like Oregon ash, big leaf maple, vine maple, madrone, Port Orford cedar, and western crabapples. Beach daisies, coastal strawberries, azaleas, and currants add beautiful color to zone 9 gardens. Native salal, also known as Oregon wintergreen, makes a beautiful hedge, and native tiger lily wildflowers add a striking freckled orange touch to shade gardens.  In the edible realm, this area is renowned for strawberries, cranberries, lily bulbs, and quality milk and cheese. 

You can grow most vegetables in zone 9 as long as you properly amend your soil. Sandy coastal areas may require extra compost to ensure adequate drainage. Inland areas are still prone to heavy clay and require organic matter to loosen and aerate them.

Zone 10

A very small segment of Southwestern Oregon now falls into zone 10a. Since the 2023 updates to the USDA Plant Hardiness zone, climate experts have identified that the southern regions of Oregon are progressively warming. This small area south of Coos Bay around Curry County is suitable for growing moisture-loving subtropical perennials outdoors. Bird of paradise shrubs, century plants, and even banana trees can thrive in this area.

Big blue hydrangeas, red crocosmia, and gladiolus are a few of my favorites for this area. Southern Oregon gardeners incorporate exotic palms, yuccas, agaves, and even citrus trees into home landscapes. Giant eucalyptus are particularly popular shade trees with gorgeous, fragrant leaves.

For vegetable growers, zone 10 is only limited by sunlight and excess humidity. The winters can be quite dark and cloudy, and crops are prone to mold or mildew infections due to the high moisture and persistent rains. Still, disease-resistant varieties and widened spacing can ensure reliable year-round yields of your favorite crops.