gardening with natives- definitions, rationales, selected plant list

Notes- gardening with natives; definitions, rationale, and a selected plant list

(notes from a recent talk I gave at the Intro to Gardening With Native Plants workshop)

(abbreviations: sp. = species, singular; spp.= species, plural)

A native plant is one growing in the region where the species evolved.  Broadly, North American natives are considered to be those that were here before the arrival of European settlers.  Some horticulturists have tended to refer to natives as those that are to native to North America, anywhere.  Botanists and ecologists are more regional in their application of the term, and some insist upon a very narrow, virtually neighborhood-specific prerequisite for something to be considered native.  In truth, while we can accurately refer to plants of the Cascades and high desert as NW natives, their ecology is likely to be very different from that which prevails in westside and coastal areas.

Near-natives: can include closely related plants from similar (Mediterranean) climates, also cultivars of wild species e.g. King Edward VII Ribes sanguineum

Native plants have evolved with and are adapted to the climate and soils of our region, and so may require less care than non-natives.  They have also evolved with the local pests, and so have developed defenses.  Native birds and wildlife depend upon them.  And by growing natives, we may to some extent be helping to keep threatened flora from extinction- like keeping cheetahs in zoos.  By maintaining native plants in our gardens and landscaping, we become more familiar with them.  And by replacing invasive nonnatives with native plants, we can in a small way remediate the harm to native flora done by Scotch broom and English Ivy land grabs.

Obtaining natives- ethics of collecting; make sure you know methods of the nursery from which you make purchases. Threatened plants are legally protected, and many rare plants are vulnerable to over-collecting. Some native lilies (Lilium, Trillium spp.) are very difficult to propagate from seed, and take around 7 years from seed to first flower- thus some nurseries may be tempted to use plants that have been poached.  Permits are available for collecting plants in limited numbers from Forest Service land; salvage programs collect native plants doomed by development; conservation districts sponsor native plant sales; some businesses online sell native seed; a few nurseries specialize in natives, and most general nurseries carry at least a few native plants. (section in Kruckeberg)

ecological approach to gardening

In thinking about plant placement, think about where this plant would occur in nature.  If in woodland, it is probably best in shade, on well-drained, acidic soils with a lot of organic material.  If in wetland, it probably likes sun to partial shade, not full shade. 

Knowing the plant’s taxonomic grouping can help.  True grasses are in general, with few exceptions, adapted to full sun, well-drained locations.  Rushes and sedges like moisture.  Buttercup family plants are mostly shade and/or moisture loving, toxic, deer-resistant.  Saxifrages (=”rock break”) are nearly all shade lovers, woodland plants that either grow in well drained soils or rocky outcroppings. 

Trees

The dominant conifers of our region are Thuja plicata (Western Red Cedar), Pseudotsuga menziesii (Douglas-Fir), Tsuga heterophylla (Western Hemlock) and Abies grandis (Grand Fir). 

Douglas Fir grows rapidly to as tall as 200 ft, often found in dryish or poor soils

Grand Fir may reach over 200 ft; generally grows in dry areas, often found with Douglas Fir

Conifers in general do best in well-drained soils, in full sun.  Hemlock and Western Redcedar are more tolerant of shade and wet environments. 

Western Red Cedar- dominant tree of coastal areas, can grow up to 200 ft tall with up to 10 ft diameter trunks in mature trees. There are many cultivars of Thuja plicata as well as other Thuja species widely available in the nursery trade, e.g. arbor vitae

Western Hemlock is fairly common in our region, often in woods dominated by Western Redcedar.  It can grow to 180 ft tall, with a more slender trunk than Redcedar.  Needles are short and of variable length, contributing to the lacy look of the foliage. (The second part of its botanical name- Tsuga heterophylla- means “different leaves”.)

Mountain Hemlock (Tsuga mertensiana) occurs at higher elevations, and at around 120 ft tall with a comparatively narrow profile, it is a somewhat smaller tree than Western Hemlock; Mountain Hemlock is more often available in nurseries. The tree grows fairly slowly and is unlikely to reach maximum heights in home landscapes.  Twenty year height is around 25 ft.; width to six feet.

Taxus brevifolia (Western Yew)- shade tolerant smaller tree, max 50 ft tall, source of  Taxol. Grows in moist mixed forests at low to mid elevations.  Coniferous, but the single seed is covered by a bright red skin.  The seed (with the exception of the red skin) is very toxic though eaten by birds. Yew is dioecious: separate trees are male or female, rarely both

Pinus contorta= montane form  Lodgepole Pine and lowland form, Shore Pine. It is a somewhat smaller (to  50 ft)  tree whose size and silhouette can vary greatly depending upon growing conditions.  Like the other conifers, it requires full sun and good drainage.  Common on coasts, sporadic in Willamette and Puget Sound areas, except San Juans

Evergreen broadleaf trees- the major one of our region is madrone Arbutus menziesii (heather family).  It is most abundant in drier areas (like Sequim and the peninsulas and islands of the rain shadow), and higher, exposed locations. Also seen on bluffs over the Sound. 

This is a large tree, beautiful in flower and fruit.  Fruit important to native birds.  Tree needs full sun and excellent drainage.  Tends to deteriorate when other trees grow up around it, shading it.  Has a reputation for being difficult to grow, but this is mostly due to its intolerance to overwatering and fertilizing.

Common name Strawberry Tree is confusing, as this is also applied to its relative Arbutus unedo, a smaller, more shrubby plant, which is sometimes labeled as a native but is not—it’s a European species.  A. unedo also is host to some 28 fungal pathogens in our region.  Arbutus marina, another nonnative sometimes erroneously labeled as native, is a hybrid of Arbutus unedo and an unknown, probably Asian, more tender species.

Deciduous broadleaf trees

Vine maple- Acer circinatum- may grow as a small multi-trunked tree or shrub; 3-30 ft, usually 10-15; more treelike habit in full sun, more shrubby in shade; leaves and tree structure may resemble Japanese maples

Needs regular water to get established; full sun to part shade; best fall color in sun

Vine maples from nurseries can be prone to a number of problems, including disease and transplant shock

Paperbark birch- Betula papyrifera- grows to 40 ft in 20 years- ultimately 80 ft; often multi-trunked; peeling white to brown bark- birches in general often suffer damage from Sapsuckers (colorful birds that drill holes in bark especially during the high-sap season, April to July)—a broad band of regularly positioned lines of holes will often be seen on the trunk several feet off the ground

Dogwood- several native species, including a tree (Cornus nuttallii – to 60 ft), shrubs (Cornus sericea- syn C. stolonifera- Red Osier Dogwood) and ground cover (Cornus canadensis- syn unalaschkensis- Bunchberry).  Dogwood trees including our native and the eastern native C. florida are vulnerable to the fungal disease anthracnose; Korean Dogwood is less susceptible, and so a reasonable choice for the NW landscape if anthracnose is a concern may be one of the cultivars that are hybrids between C. nuttallii and C. kousa

Shrubs

Cornus sericea- red osier dogwood- shrub grows in stoloniferous clumps often to 12 ft in diameter, 15 ft tall- clusters of small white flowers followed by white berries. Numerous cultivars, including dwarfs and variegated forms, forms with varying stem color (gold).  Some disease problems particularly in the cultivars. Inflorescence appears much different than in the trees and ground cover Cornus; in those, the four “petals” that make the flowers showy are actually white (or pink, in cultivars) bracts; in Red Osier, the inflorescence consists of many small, bractless flowers

Rhododendron macrophyllum- most widespread native Rhody in our region- large, evergreen; pink flowers.  Typically grows on edges of coniferous woods, and part shade is its best spot.  Prefers somewhat acidic, moist, well-drained soil.  Surprisingly hard to find in nurseries.  May be susceptible to rhododendron weevil, which is quite a problem in our area—do not plant in or near a spot where weevil damage (notched leaves, brittle brown flower buds) has been observed on Rhododendron or other shrubs. Two other PNW native Rhodies- both deciduous.  One white-flowered Rhododendron albiflorum, northern and upland sp., considered very difficult to grow and not available in nurseries.  R. occidentale – Western Azalea- is a tall, deciduous shrub with fragrant, showy peach colored flowers, grows Oregon coast range southward.  Easy, sold in nurseries.

Ninebark- Physocarpus capitatus- Rose family-  deciduous multi-trunk shrub to 8 ft tall, 6 ft wide, attractive clusters of small white flowers May/June.  Several cultivars of closely related species on nursery market.  Reliably browsed by deer.
Likes somewhat moist soil in full sun to part shade

Huckleberry- in our region, one widespread evergreen species (V. ovatum) bearing blue-black fruit and one somewhat less ubiquitous deciduous version (V. parvifolium), with many small, shiny red fruits valued for culinary use.  Several other native Vaccinium species.  Genus Vaccinium also includes the blueberries, edible and ornamental cultivars.

Honeysuckles

Lonicera involucrata, Twinberry- erect shrub

Lonicera hispidula and L. ciliosa-

L hispidula bears smaller, yellow to pink or pinkish purple flowers, orange-red berries, can have a semi-erect, shrubby or vining habit, grows in part shade to sun. 

L. ciliosa is more shade loving, vines can run 20 ft up into trees, large bright orange flowers May to July, orange berries.  Perennial, deciduous in our region. Susceptible to blight, mildew.

Berries of these  Lonicera species considered upalatable, inedible, possibly toxic.  Another, L. caerulea, has been bred as a potential agricultural crop.

Ribes sanguineum- Red Flowering Currant.  Brightest thing in spring, blooming Feb through April.  Usually deep pink, but ranges from light pink (occasionally white) to light red.  Loved by hummingbirds.  Flowers followed by blackish berries with chalky white dusting, midsummer. Berries are nontoxic but said to be quite unpalatable to humans, though eaten by birds.  Popular cultivars include King Edward VII (deep pink flowers) and Icicle (white flowers).  Requires excellent drainage.

Philadelphus lewisii- Mock Orange- tall, showy, drought-tolerant deciduous shrub for full sun.  Fragrant white flowers spring through late summer.

Spiraea spp (Rose Family)- two PNW species; S. douglassii is common in our area.  3 to 8 ft tall, long pointy inflorescences of small pink flowers blooming mid to late summer, grows on edges of irrigation channels, drainage ditches, wetlands.  Full sun to part shade.  

S. densiflora- more alpine in distribution, but a valuable horticultural plant which blooms May/June to midsummer; much more compact than S douglassii and more drought-tolerant; usually 3 ft tall and wide though it can be larger; showy “powder puff” inflorescences

Rosa spp.- R. nutkana, pisocarpa, gymnocarpa.  R. nutkana is larger, found usually in full sun.  Can be rangy and rampant; good for holding slopes, and often seen on bluffs. R. gymnocarpus has smallest leaves and flowers, “baldhip”=  calyx absent by the time the plant is in fruit. Rare shade loving rose.

Myrica californica- Pacific Wax Myrtle- moist to somewhat dry soil, sun to shade, to 8 ft and can form dense thicket.  Small yellowish flowers in catkins, separate male and female catkins on the same plant, crescent-shaped waxy evergreen leaves. Similar and closely related but smaller and deciduous is Myrica gale. Nitrogen-fixing root nodules. (Other nitrogen fixers in our flora include Alders, Ceanothus, and most legumes including Lupines.)

Mahonia nervosa, Mahonia aquifolium- two widespread spp of Oregon Grape (Barberry Family).  M. nervosa (Low Oregon Grape) has more numerous leaflets, prefers more full shade.  M. aquifolium (Holly Leaf Oregon Grape, Tall Oregon Grape) has more toothy, shiny leaves (causing confusion with holly); likes sunny woodland edges.  Easy distinction from holly:  holly leaves are alternate; Mahonia leaflets are opposite.  Mahonias bloom (yellow) April/May, then set attractive dark blue fruit.  Roots used medicinally and berries are edible. 

Perennials for Shade

Anemone spp. – numerous NW species, some of open meadows and rocky montane habitat; A. deltoidea and A. oregana are woodland spp. of our region. A. deltoidea has showy white flowers to 3” wide, on stems to 15”. The low-growing plant is deciduous, spreading on slender rhizomes.

Dicentra formosa-  Bleeding Heart- attractive deciduous perennial for shade; spreads by seeds and rhizomes. Heart-shaped pink flowers in early summer. May go summer-dormant due to heat and drought, but can be kept going (leaves alive, some late flowers) through summer with adequate shade and regular water. Spreads via rhizomes and seed.

Erythronium spp.- 4 NW species; two montane and two lowland.  The latter are E. revolutum (Pink Fawn Lily or Coast Fawn Lily) and E. oreganum (Giant Fawn Lily).  Another common name for the genus, annoying and mystifyingly irrelevant, is Dog Tooth Violet. The plants are not remotely related to violets, and in no way resemble them.

E. revolutum occurs in sometimes large populations in woodland areas and near water along the coast from BC to Oregon.  Flowers in spring, medium pink to white. Despite their delicate appearance, Erythroniums are fairly easy to grow in very well-drained soil in moist shade.  Slugs and deer will eat them.

Heuchera and friends (Saxifrage Family)

Tolmeia, Tellima, Mitella, Tiarella

Saxifrage = “rock break”—these plants in general require excellent drainage, and are often found growing in damp, rocky spots near streams in open woods. All plants in the group like at least part shade; Heuchera is particularly resentful of clay.

Available at garden centers- many cultivars of Heuchera spp., also Heucherella (Heuchera/Tiarella cross).  These are all woodland species, deep to partial shade; Tellima is more sun-tolerant.  All have small white to pink flowers.  Tellima and some Heucheras are evergreen.  Deer will reliably munch the flowers of this group, usually leave the leaves alone.  In most of these, the primary leaves are basal.  If leaves grow on the flower stems, often these will deteriorate soon after the flowers die.

Tellima grandiflora, Fringe Cups, tolerates a range of soils but is significantly more handsome in good garden soil with light shade.  Handsome evergreen leaves form a spreading clump, with long-lasting tall, slender, arching flower stems in summer. Abundantly self-seeding.

Tolmeia menziesii- Piggyback plant, Youth-on-age; semi-evergreen; brown flowers; new leaves may arise at the juncture of mature leaf and petiole (stem of leaf)

Viola spp.- at least 20 NW species, with yellow or white to purplish flowers.  Low-growing, shade and moisture loving ground cover, usually deciduous except for V. sempervirens (with yellow flowers).  Violas spread via rhizomes and/or stolons, self-seeding.

Maianthemum spp.- all bear white flowers followed by berries. Lily family. M. racemosum and M. stellata, formerly Smilacina—False Solomon’s Seal—tall woodland lilies with small white flowers in racemes. Flowers in April to June are followed by berries, red in M. racemosum and green turning to blue/black in M. stellatum. Rhizomatous plants with unbranched stems. Slugs and deer will munch heavily. Related, somewhat similar looking plants in similar habitat include Disporum spp. and Streptopus spp.

See Maianthemum dilatatum under ground covers.

Petasites spp- daisy family, deer-resistant, large plant (to 30”), part shade, tolerates range of soils.  Inflorescence a somewhat umbel-shaped head of small white to pink fringed-looking flowers on stalks. Palmate Coltsfoot, Petasites palmatus, most common in our region- large heart shaped, deeply divided, matte-surface leaves.

Aruncus dioicus- Goatsbeard- rose family, resembles Astilbe, part shade, moist with drainage, large, deciduous, divided foliage, spiky/feathery inflorescences of small white flowers mid summer. Woodland edges, often gentle slopes. Dioecious (separate male and female plants)- flowers a bit different, appearing a bit fluffier on male plants; female plants bear attractive seed pods.

Trillium ovatum- showy woodland relative, growing from a bulb. Most widespread Trillium in our region- white flowers early spring to midsummer, needs very well drained soil with a lot of organic matter, moist shade.  Slugs, gophers and deer will steal them.  Our native Trilliums are hard to find in nurseries, and care must be taken to buy from reliable sources who are not poaching.  There are a couple of additional, larger, less widely distributed NW species, including T. albidum.

Perennials for Sun

Allium cernuum – Nodding Onion- showy native onion—small edible bulbs and chivelike leaves, delicate bright pink to white flowers midsummer in umbels to 15” tall.  One of several smallish, white to pink, pretty native onions. Easy to grow, multiplies via bulb offsets and self-seeding. Like other bulbs it prefers well-drained soils but will tolerate even heavy clay, seasonally boggy to droughty soils.

Aquilegia- Columbine- A. formosa is our most widespread Columbine.  Graceful, orange to reddish flowers attract butterflies and hummingbirds.  Likes moist, well-drained, sunny conditions or dappled shade.  Self-seeds generously, deciduous, taprooted.  Columbines generally tend to hybridize easily when grown near other Columbine species. Columbines often do poorly in containers.

Camas- full sun to part shade, moist soil, tolerates heavy clay soils, seasonally boggy conditions.  Lily family member that is comparatively easy to grow from seed (good germination) though it takes about 4 years for the first florets to appear, and a couple more years for a full inflorescence.  Contractile roots cause bulbs to move downward in soil.  3 PNW species, Camassia quamash, C. cusickii and C. leichtlinii; C. quamash most common.  Showy racemes of purple flowers in early summer.  10-20” tall, strap shaped somewhat fleshy leaves. 

Campanula rotundifolia- deciduous plant to three ft tall (usually shorter); basal leaves heart-shaped, leaves on flower stems linear/grasslike; graceful slender stems support numerous showy bell-shaped flowers in delicate shades of lavender, occasionally white- June through September.  Spreads at a modest pace via slender rhizomes and self-seeding. Likes well-drained ground, sea level to subalpine, moderately drought-tolerant.

Eriophyllum lanatum – Wooly Sunflower- low-growing, gray-green foliage, inch-wide, very bright yellow daisylike flowers May through September- full sun, excellent drainage, drought-tolerant. Another, very confusing common name is Golden Yarrow (the plant in no way resembles Yarrow).  Height is quite variable, from more erect lowland forms that may reach 30” tall, to nearly prostrate montane varieties. The plant typically grows in open, dry, often rocky habitat, gravelly roadsides etc.

Iris tenax- full sun to part shade, stiff evergreen leaves, usually purple flowers May/June with yellow and white markings; occasionally white, yellow or pink. Meadows, sunny woodland edges, well-drained moist to dryish, acidic soil.

Lilium columbianum- Columbia Lily, “tiger lily”- blooms early summer- orange to gold, strongly reflexed petals with speckles- wide range, scattered, sometimes large populations in sunny meadows and dappled forest edges up to 6000 ft, BC to CA, bulb, needs good drainage, moisture, organic material.  Guaranteed to be eaten by deer, rabbits, slugs, gophers, rats...

Lewisia spp- Bitterroot- Purslane family-- montane and eastside but can be grown here with special attention to drainage.  Some collectors keep Lewisia in pots and turn sideways in winter, or hold under eaves.  Does best in medium with very sharp drainage, somewhat alkaline- pumice, perlite, rocks.  Most tolerant of our weather and soils is L. cotyledon, which is widely available in garden centers.  Another relatively easy sp. for the garden is L. columbiana- basal succulent leaves, small flowers on long stems.  Other species are beautiful but fussy, some deciduous.

Lupines- large group spp throughout west, perhaps 80 native to the NW.  Full sun, loved by butterflies.  Possibly short lived but spread by plentiful, long-lived seed.  Hard to keep in containers (possibly due to need for rhizobial associations), may be best grown from seed. Specific inoculants are available (see Roose Green Solutions, which sells inoculant and has an excellent page on nitrogen fixation). Bigleaf Lupine, Lupinus polyphyllus, is a large species widespread in our area—to 4 ft tall, blooms early summer, tall spikes of purple flowers. Needs good drainage; grows on moist to dryish soil; open, sunny meadows are its natural location but it can be found on roadsides and woodland edges, persisting over the years via large woody rhizomes and self-seeding. Deciduous, tends to deteriorate after blooming.  Seed is highly toxic, looks like lentils; easily collected for propagation, and long-lasting.

Mimulus- (Monkey Flower)- in the figwort family with the characteristic “lipped” corolla (like snapdragons) adapted for insect pollination.  Many species throughout the west, several in PNW.  Most widespread in our region is M. guttatus, a plant of wetlands and streamsides which is tall, yellow flowered, moisture loving, full sun to part shade, blooms late spring through summer.  Most species are yellow, orange, pink.

Oenothera spp.- Evening Primrose- numerous NW species; O. hookeri and O. biennis are perennial to biennial, tall, deciduous.  Flowers are large, bright yellow and showy, mid to late summer.  Leaves are undistinguished, and it is rare to find the plants in nurseries.  Seed is easy to collect and propagate.

Penstemon- over 100 native species, some meadow and some rock garden plants, herbaceous or subshrubs, deciduous or evergreen, some prostrate, others erect to 36”. Mostly dryish habitats, sunny/rocky; the comparatively tall sp Penstemon serrulatus grows in wetter sites, coastal to subalpine.  All penstemons have tubular flowers, most often purple (some pinkish, at least one yellow), attractive to hummingbirds. Rock Penstemon, P. rupicola, is very low-growing, blooms May-August, deep pink flowers, evergreen foliage.

Potentilla gracilis – Graceful Cinquefoil- rose family; small shrub with deciduous, much-divided foliage, small yellow flowers late spring through early summer.  One of numerous native Potentilla species, which range from very low, prostrate ground covers, mostly herbaceous, moist to dryish ecology, coastal to middle elevations.

Sidalcea spp- mallows- several PNW spp, medium to very tall plants of woodland edges and meadows.  Full sun, great for butterflies.  Delicate flowers pink to white. Several checker-mallows, including S. virgata, S. nelsoniana and S. hendersonii—are gynodioecious (different plants may have only hermaphrodite flowers, or only female flowers).  The hermaphrodite flowers are noticeably larger and somewhat paler than the female flowers. Hermaphrodite plants will produce seed; female plants will produce seed only if a hermaphrodite is nearby.  Sidalcea spp grown together will often hybridize.  Sidalceas are very showy and long-blooming; S. hendersonii blooms June through September (at least). Deciduous.

Sisyrinchium spp.- Iris family- several PNW species.  Botanically changeable, with several taxonomic shifts within and among species.  Most widespread in our region are S. bellum (or S. idahoense), S. douglasii (or Olsynium douglasii), and S. californicum. All species have long, narrow, grasslike leaves, small flowers early through late spring.  S. bellum has blue-violet flowers, S. douglasii has somewhat larger rose-purple flowers, and S. californicum has golden yellow flowers. Full sun to part shade in moist meadows. The plants spread via short, wiry rhizomes and self-seeding.

Stachys cooleyae- rampant plant for full to part sun, moist well-drained situations- ditches, wetland edges- pretty common in our area.  Horehound scent, deep pink to purplish flowers loved by hummingbirds.  Spreads by seed and rhizomes. May be prone to powdery mildew if leaves stay too wet due to weather, overhead watering, shade or crowding.

Annuals-

Clarkia (Evening Primrose Family)—generally available only as seed; Clarkia (Godetia) can be found occasionally in “wildflower” mixes or alone.  There are several spp; C. amoena is particularly lovely, 6”-3 ft (most commonly around 2 ft)- varying shades of pink to white, with petal spots.  Clarkia may be happiest in spring and fall, not in the hottest summer weather.

Collomia grandiflora (Phlox family)- Collomia blooms early to midsummer, white through yellow, usually orange. There are several other annual species and one perennial species of Collomia

Both Clarkia and Collomia are very showy plants of meadows, roadsides and sunny woodland edges.  Both self-seed extravagantly.  Will tolerate clay but love good drainage.

Plectritis congesta (Sea Blush, Valerian family)- one of three NW species, all annuals. Showy clusters of small pink flowers atop plants 6-30” tall- grows in full sun in seasonally moist meadows at low elevation, often close to the coast

Ferns

Athyrium filix-femina- Lady Fern- tall, deciduous

Blechnum spicant- small fern, semi-evergreen

Adiantum pedatum, (syn Adiantum aleuticum)- Maidenhair fern- delicate deciduous fern for moist well-drained shade, rocky streamsides

All ferns prefer shade, though their tolerance for a bit of sun varies.  The ubiquitous, rambunctious, large evergreen Sword Fern tolerates sun well.  Deer fern will not appreciate direct sun, but will not immediately fry.  The softer fronds of Maidenhair despise direct sun and hot weather.

Deer will not eat most ferns, and slugs seem to have little impact.

Ground covers

Cornus canadensis (syn C. unalaschkensis)- Bunchberry- prostrate Dogwood with attractive semi-evergreen leaves, showy white flowers in mid-summer, followed by red berries. Rhizomatous, prefers shade, moist, well-drained acidic soil.

Linnaea borealis- Twinflower (Honeysuckle Family) named by Linnaeus after himself, honeysuckle family, small, graceful, evergreen, trailing plant with attractive leaves and tiny pink funnel shaped flowers borne in pairs in early summer. Rapid but not invasive, can cover ground to form a mat over many square feet. May take years from seed to bloom; may be best to propagate by cuttings or divisions, easy.  The plant is self-incompatible, so a clone that blooms amply will not produce seed (dry capsule)

Vancouveria hexandra- inside out flower- (Barberry Family) to 1 ft tall, semi-evergreen to deciduous with small white flowers in midsummer.  Can fill fairly large spaces, spreading via rhizomes and self-seeding. Closely related to Epimedium, barberry family.

Oxalis- two spp in our region, one with yellow and one with pink flowers.  The latter, O. oregana, is often available in nurseries and can provide rapidly spreading ground cover in moist shade.  “clover”-like leaves, five-petaled flowers.

Asarum caudatum- Wild Ginger- moist shade, rhizomatous, evergreen, low-growing, forms mats- brownish to green-yellow flowers often borne under the heart shaped, sometimes mottled leaves.  Ginger scent to leaves when crushed.  Roots are edible, but many plants in the family are toxic, so caution is advised with other plant parts.

Maianthemum dilatatum- False lily of the valley- (Lily Family)- heartshaped leaves with conspicuous parallel venation.  Moist shade.  Deciduous, disappears completely in winter; aggressive, spreads reliably via rhizomes and stolons. Small star-shaped flowers in erect cylindric clusters rise a few inches above the low, broadly heart-shaped, abundantly ground-covering leaves.

Arctostaphylos uva-ursi- Kinnickinnik- (Heather Family)- full sun to shade, evergreen, well-drained, drought-tolerant; slow to establish, but eventually makes a thick, low, shrubby ground cover to about a foot high; good for holding slopes

Trientalis latifolia- Star flower- (Primrose Family) -deciduous, to 4” tall, beautiful pinkish, 6-7 pointed flowers in spring/early summer.  spreads via stolons, tubers and seeds.  Usually not a dense ground cover, though in good garden soil may provide more coverage.  Downside= deterioration of leaves after flowering but with a bit of water would persist longer. Very similar smaller plant with pure white flowers is T. arctica

Graminoids

Deschampsia cespitosa – Tufted Hairgrass- tall, graceful semi-evergreen grass; moderate water needs, full sun.

Elymus mollis- dune grass; dominant native grass on coastal beaches prior to introduction of the invasive European beach grass

Carex spp.- wetland grasslike plant, many spp. and cultivars.

Juncus spp.- rushes; wetland grasslike plants.  Most common in our region, and also widely available in nurseries, is J. effusus, with tall, hollow, round culms and attractive dark brown florets. Evergreen. Full sun to part shade.

A somewhat smaller, very attractive Juncus is J. acuminatus, Spike Rush, which is semi-evergreen to deciduous.