native plants for oregon’s willamette valley

Linda R McMahan, Ph.D.

Botanist and Community Horticulturist

Oregon State University Extension Service

linda.mcmahan@oregonstate.edu

Native Plants for Oregon’s Willamette Valley

Why native plants? The most reliable speciesDifferent plants for different

purposesWhich species attract the wildlife

you want to encourage and enjoy

What You Might Like to Know

Native camas, Camassia sp.

Why Native Plants

Native Plants are: Already adapted to our weather

and soilsReminders of our natural

surroundingsSupport for local insects, birds and

other wildlifeBeneficial for stream healthHardy and relatively disease freeBeautiful

Western mock orange, Philadelphus lewesii

Trees in the Landscape

Grand fir, Abies grandis and western red cedar, Thuja plicata

• Structure

• Shade

• Protection

• Vertical

Interest

Oregon ash – Fraxinus latifolia

Oregon ashTree to 80 ft Tolerates moist /

seasonally wet soilsWildlife value:

FoodCoverNesting sites

Oregon oak

Quercus garryana

Oregon oakTall, deciduous,

slow-growing Fallen leaves can

suppress weeds & work well in compost

Cannot tolerate summer irrigation

Bigleaf maple

Acer macrophyllum

Big Leaf MapleAcer macrophyllum

Stately treeUse large leaves

for weed suppression or compost

Once established requires no added water, but can support a shady lawn

Ponderosa pine – Pinus ponderosa

Ponderosa pineTall, but usually ok

near structuresFull sunDry sites east of

CascadesWest of Cascades,

the Willamette Valley form withstands wetter sites

Western red cedar – Thuja plicata

Western red cedar

Grows near but not in water

Sun, part sunMature tree can

be very tall

Vine maple – Acer circinnatum

Vine maple

Graceful understory tree, prefers part shade

Slow growingReadily available

Osoberry (Indian plum) – Oemleria cerasiformis

OsoberryLight shade• Drier areas• March blooms• “Plums” bird food• Easy to grow• Available at nurseries

Shrubs in the Landscape

Red flowering currant, Ribes sanguineum

• Shelter

• Erosion Control

• Wildlife Value

• Eye Level Interest

Mock OrangePhiladephus lewesii

Mock orange

o Fragrant, good nectar sourceo Fast grower, drought toleranto Sun, part shadeo Butterfly host

Nootka Rose – Rosa nutkana

Nootka roseFull sun in drier

areasBank stabilizer,

spreads underground

Flowers provide nectar, hips food for wildlife

Oregon grape – Berberis aquifolium

Oregon grape

Evergreen, forms colonies

Berries and nectar support wildlife

State flower of OregonWidely available

Blue elderberry – Sambucus mexicana

Blue elderberryTall, multi-stalkedSun, part sunAverage to dry siteWhite, flat-topped

flower clustersBlue berries feed

wildlife

Red flowering currant – Ribes sanguineum

Red flowering currant

Blooms Feb/MarShade/part-sun,

banks and drier areas

Fast growing, readily available

Drupes in late summer for birds

Hummingbird pollinated

Red osier dogwood – Cornus sericea

Red osier dogwoodOccurs naturally

along streams but tolerates drier conditions

Full to part sunRed winter twigsHost for native

butterfliesLook for local plants

Snowberry - Symphoricarpus albus

SnowberrySpreads to

stabilize banksSpreads to

increase coverBluish, soft foliageFruits provide food

through the winter

Groundcovers and Herbaceous Plants in the Landscape

Ladyfern and oxalis

Garden interestProtection for

compaction by rainHiding places for

small creaturesHelps prevent

erosion

Sword fern – Polystichum munitum

Sword fernPart or full shadeOne of the best

plants for bank stabilization

Great landscape ornamental

Easy to findEasy to

transplant and relocate

Wild strawberries – Fragaria—3 native species

Ground cover, spreading by runners

Some species prefer shade; others sun

Nectar for butterflies and other insects

Butterfly caterpillar hosts

Lady fern – Athyrium felix-femina

Unfurling spring fronds

Lady FernPrefers sun or part

sun, good soil moisture

Good for bank stabilization

Winter deciduousDelicate soft foliage2-4 feet tall

Wood sorrel – Oxalis oregana

Wood sorrelAggressive

groundcoverFull to part shadeOnce established,

difficult to removeWill tolerate dry

shade and go dormant in dry summers

Camas - Camassia species

CamasCommercially

available bulbSpring bloomingNeeds spring

moistureNeeds summer

dry

Oregon iris – Iris tenax

Oregon iris

Reliable native iris, late spring blooms

Tolerates drier sites

Yellow monkey flower – Mimulus guttatus

Yellow monkey flowerMoist soilSun/part-shadeSpreads to

become a ground cover

Nectar Seeds provide

food for wildlife

In Summary

Natives add or enhance wildlife habitat

Look at all levels-trees shrubs, herbaceous plants and groundcovers

Match the requirements of the plant to its new habitat

Plant directly into native soil

Wild bleeding heart, Dicentra formosa

In Summary

Take care of plants for the first 2-5 years after planting—some will require additional irrigation during this time

Group plants with similar needs together

Enjoy your new connection with Oregon native plants

Wild bleeding heart, Dicentra formosa

Thank YouPhotos by the

authorPresentation may

be used freely for educational purposes

For all other purposes, contact the author at linda.mcmahan@oregonstate.edu

Stream violet, Viola glabella