The document provides recommendations for native plant species well-suited for gardens in Southwestern Oregon, highlighting plants unique to the region as well as those shared with other parts of Oregon, California, and the Pacific Northwest. Examples are given of various native shrubs, trees, ferns, flowers and groundcovers including their characteristics, growing requirements, and images. The document aims to educate homeowners on selecting native plants well-adapted to the climate and conditions of Southwestern Oregon.
1. Native Plants
for
Southwestern
Oregon
Linda McMahan
OSU Extension
Yamhill County
Scarlet monkeyflower, Mimulus
cardinalis (SW Oregon & CA)
2. Southwestern Oregon is Unique
Rainfall high in winter,
low in summer
Warmer high temps
than most of OR but
can be colder in winter
Shares some features
& plants with Northern
CA
Shares many plant
species with the rest of
the Pacific Northwest Oceanspray, Holodiscus discolor,
shared with much of OR
3. Southwestern Oregon is Unique
Share some species
with Cascades
and/or Eastern OR
The region is
amazingly diverse,
with high mountains,
soil variations, fertile
river valleys, and Wikipedia.org
rocky outcrops
4. Today‘s Goal
Feature plants native to
Josephine County
Many share plant
distributions with other
parts of the Oregon or
California
Some plants native to
Oregon but not
common in Josephine
County may also be
grown here, but we will Rocky Mtn maple, Acer
not cover those today glabrum, shared with
Cascades and Eastern OR
5. Plants Unique to Inner
Southwestern Oregon
Some will also occur in neighboring counties or in
Northern California
6. California fuchsia, Epilobium
canum (Zauchneria californica)
Native to California
as well
A mounding and
spreading sub-shrub
for full sun or very
light shade
Many cultivars
available
Attracts
hummingbirds
Wayne‘s silver form
7. Scarlet monkey flower,
Mimulus cardinalis
Herbaceous
perennial
Prefers part-shade
and moist soils
Native to SW OR
and into CA and
other SW US states
M. cardinalis is shown with native
yarrow form (Achillea millefolium)
8. Skunkbush, Rhus trilobata
Sun to light shade
Shrub 2-8 feet and
spreading
Zone 3/4
Food and cover for
wildlife
Drought tolerant,
good for sunny and
dry spots
Yes it is related to
poison oak but OK for
gardens http://oregonstate.edu/dept/ldpla
nts/rhtrilob.htm
9. CA black oak, Quercus kellogii
Deciduous tree, 40-
80 ft. with open,
rounded crown
Sun or light shade
Drought resistant,
succeeds in dry,
sandy, or gravelly soil
USDA Zone 7
Mostly SW OR but
does go north to
Lane County http://oregonstate.edu/dept/ldplants/
quke.htm
10. Jeffrey pine, Pinus jeffreyi
Conifer to 80 or more
feet
USDA Zone 6
Mountains from
southern Oregon to
Sierra Nevada's
Fragrant needles—
three needle bundles,
larger cones than
Ponderosa pine
Can grow on
serpentine soils (low
calcium-magnesium
ratio, high in heavy
metals)
http://oregonstate.edu/dept/ldplants/pijef.htm
11. Giant Chain Fern –
Woodwardia fimbriata
―Choice‖ large fern,
each frond to 6 feet
Evergreen
Needs regular moisture
and part-shade to sun
Possibly needs frost
protection, depending
on the site
Share distribution with
northern California
Unique spore structures
on frond undersides Photos: Wikipedia.org
12. California wild grape, Vitis
californica
Native to California
and SW Oregon
Cultivars available,
‗Roger‘s Red‘ is one
available-may be a
hybrid
Vigorous deciduous
vine popular in
landscapes
Red fall color Photo: Wikipedia.org
Propagates easily
from cuttings
13. Golden inside-out-flower,
Vancouveria chrysantha
Perennial evergreen
herbaceous plant
spreading by
rhizomes
Golden blooms in
spring
Sometimes called
the Siskyou inside-
out-flower
Photo: Mrs. WD Bransford,
Considered to be Lady Bird Johnson
―choice‖ by some Wildflower Center, Univ.
gardeners so worth Texas at Austin
looking for
14. Plants Shared with Cascades
and/or Eastern Oregon
Many of these are commonly available in the plant
trade
15. Green manzanita,
Arctostaphylos patula
Evergreen shrub, to
7 ft, dark bark
Sun or light shade
Best on well-
drained soils, does
well on dry sites
USDA Zone 5
SW Oregon to
Mountains north
and south http://oregonstate.edu/dept/ldp
lants/arpat.htm
16. Rocky Mountain maple, Acer glabrum
Small broadleaf
deciduous tree to
30 ft, often multi-
stemmed
Sun to part shade
USDA Zone 4
Distribution shared
with Cascade Mtns http://oregonstate.edu/dept/ldpl
and Eastward ants/acgl.htm
17. Mountain mahogany,
Cercocarpus ledifolius
Broadleaf
evergreen shrub or
small tree to 15 ft
Sun and dry, well-
drained soil
USDA Zone 6
Distribution shared
with mountains
and areas to the
East http://oregonstate.edu/dept/ldplants/
celed.htm
18. Creeping Oregon grape,
Berberis (Mahonia) repens –
Evergreen
shrub/ground
cover
Spreads
underground
USDA Zone 5
Works well with
snow cover
http://oregonstate.edu/dept/ldplants
/mare.htm
19. Rabitbrush – Ericamera
(Chrysothamnus) nausosa
Shares distribution
with mountains
and east of the
Cascades
Grey foliage
Drought tolerant
USDA Zone 7
Neutral to slightly
alkaline soil
20. Sulfur buckwheat, Eriogonum
umbellatum
Drought tolerant
buckwheat, needs
good drainage
Low-growing
Flowers variable
yellow/gold
Needs good
drainage to thrive
Photo: Stan Shebs, Wikipedia.org
21. Fremont silk tassel, Garrya
fremontii
Evergreen shrub,
many-branched, 5 to
15 feet
Sun or part shade,
drought tolerant
USDA Zone 6
Requires good
drainage
Perhaps better
adapted to the area Photo: A. Barra, Wikipedia.org
than G. elliptica
22. Mahala mat, Ceanothus prostratus
Woody groundcover
Needs good
drainage
Blue flowers cover
plant under
favorable conditions
Full sun or filtered
shade
Especially good for a
rock garden
23. Sitka Mtn ash, Sorbus sitchensis
Deciduous shrub or
multi-trunked small
tree to 10 ft
Sun or light shade
USDA Zone 5
Flat topped, white
flowers, red fruits
and good fall color
Photos: top, Linda R McMahan, bottom,
http://oregonstate.edu/dept/ldplants/sosit
.htm
24. Pink flowered wood sorrel,
Oxalis oregana var. smalliana
Now classified just
as O. oregana
Pink flowered form
less aggressive and
slightly larger than
white flowered
form
Pink flowered form
more local to SW
Oregon
25. Plants Shared with
Willamette Valley and North
These are usually commonly available in the nursery
trade and generally will do well in SW Oregon
26. Umbrella plant, Darmera peltata
Herbaceous
water-loving plant
with giant leaves
Spreads on
ground-level
rhizomes
Magnificent
foliage and
flowers Photos: Linda McMahan on
the Rogue River and in
Flowers emerge cultivation
before leaves
29. Wild bleeding heart, Dicentra formosa
Spreading ground
cover, spring
blooms
Deciduous in
summer without
supplemental
irrigation
Cultivars are
available
30. Camas Camassia leichtlinii
Sometimes
available as a bulb
in garden centers
Require wet winters
and dry summers
Prefers full sun but
part-shade OK
A native Indian
heritage plant
35. Fairy bells, Prosartes (Disporum)
hookeri or P. smithii
Shady, moist sites
Good for
woodland garden
Spring flowers,
summer fruits
Easy to grow from
seeds
38. Check out the
recommended
requirements for
each species
Provide water to
establish, even if
the species is Cultural
drought-hardy Requirements
Refrain from too
much fertilizer-
native plants are
usually adapted
to our typical
soils Douglas iris (Iris douglasiana)
and Viola adunca
39. Leave enough
space—some
natives may
grow larger than
anticipated
Cultural
Many can be
pruned, but Requirements
some gardeners
prefer the
natural forms
Prune multi-
stemmed shrubs Desert parsely (Lomatium sp.)
from the base and snowberry
(Symphoricarpos sp.)
40. Don‘t assume
plants are ―deer-
proof‖
If you want
plants to self-
seed or provide Cultural
berries for
wildlife, don‘t Requirements
Ocean spray (Holodiscus
discolor) and osoberry
(Oemleria cerasiformis)
41. For More Information!
Kruckeberg, Arthur R. 1996. Gardening with Native
Plants of the Pacific Northwest, 2nd edition, University of
Washington Press, Seattle, WA
Yamhill County, OSU Extension Ecogardening at:
http://extension.oregonstate.edu/yamhill/eco-
gardening
Selecting native plants for home landscapes in Central
Oregon at:
http://ir.library.oregonstate.edu/xmlui/bitstream/handle
/1957/19858/ec1623-e.pdf
Oregon Flora Project (interactive maps and photos) at:
http://www.oregonflora.org/