Plant Catalog

Viburnum opulus

• Mature Height: 10'-15'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics: Attractive species for landscaping and wildlife browse-birds and small mammals in particular. Flowers are white clusters in late spring. Likes cool woods, thickets, rocky shores and slopes. Flood, disease and insect tolerant. Transplants easily and produces edible berries. 

Rosa gymnocarpa

• Mature Height: 3'-5'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Named "baldhip" due to the crown of sepals falling away from the fruit early. Attractive upland species with an odd number of toothed leaflets, pale pink to rose flowers with 5 petals in May and June. Orange to red fruits. Likes open to wooded areas. 

Corylus cornuta var californica

(California Hazelnut)

• Mature Height: 12'-24'
• Moisture: Moist - dry, well drained
• Exposure: Part shade, full shade to full sun 
• Characteristics: Many stemmed shrub to small tree. Flowers before leaves in the spring. Spherical, edible nuts in tubular husks. Likes moist but well drained thickets, clearings, forests and upland environments. Tolerates strong winds but not maritime exposure. 

Sambucus nigra ssp caerulea

• Mature Height: 15'-20'
• Moisture: Moist to dry 
• Exposure: Partial shade to full sun 
• Characteristics: Large deciduous leaves, showy white flower clusters. Blue berries which are edible and favorable for wildlife. Fast growing once it's established. Likes stream banks, swampy thickets, moist clearings, open forest and lower elevations. 

Spiraea douglasii

(Hardhack)

• Mature height: 3'-6'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics:  Multi-branched, pink tiny flowers in clusters. Widely distributed in a variety of sites including tolerance to salt spray and shoreline habitat. Completes with reed canary grass.  Likes stream banks, swamps, lake margins and damp meadows. 

Ribes aureum

• Mature Height: 4'-7'
• Moisture: Moist to dry
• Exposure: Part shade to full sun 
• Characteristics: Drought and standing water tolerant and very adaptable. Flowers golden yellow blooms in early spring. Edible yellow, red or black berries which are also important for wildlife species. Nectar is provided for hummingbirds, butterflies and bees. Commonly used in ornamental landscapes. 

Mahonia nervosa

(Dull Oregon Grape)

• Mature Height: 1'-2'
• Moisture: Moist to dry, well drained
• Exposure: Shade to full sun
• Characteristics: Bright yellow flowers which transform into edible blue berries. Evergreen with leaves like holly. Likes open to closed forest. When planting as bareroot, it is advised to defoliate the first year so the new buds will set. 

Physocarpus malvaceus

• Mature Height: 2'-7'
• Moisture: Moist to dry,
• Exposure: Part shade to full sun 
• Characteristics:  Deciduous shrub predominantly found East of the Cascade Mountains in forests, woodlands, and oak scrub. This species has white flowers with hairless branches and shreddy bark. The leaves are 3-5 lobed with serrated edges. The medium shrub provides nesting habitat for small birds.

Philadelphus lewisii

• Mature Height: 6'-12'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Upland species. Bright white fragrant flowers. Strong wood. Likes open forest, forest edges, moist rich sites. 

Rosa nutkana

• Mature Height: 6'-8'
• Moisture: Moist to dry
• Exposure: Part shade to full sun 
• Characteristics: Attractive, large, pink blossoms, purple-red round hips, easily spreading to form thickets.  great for landscaping and restoration in open habitats. Tolerate some salt spray in shoreline habitats. Good option for erosion control.

Holodiscus discolor

• Mature Height: 8'-12'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Several main stems, clusters of lilac-like white flowers which turn brown and remain over winter. Likes dry to moist open sites and works well in landscaping. 

Oemleria cerasiformis

• Mature Height: 10'-15'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: The first shrub to flower in spring. Leaves have a cucumber smell when crushed. Green to white flowers with peach and/or purple fruits. Likes dry to moist woods, stream banks and roadsides. 

  Physocarpus capitatus

• Mature Height: 10'-15'
• Moisture: Wet to moist
• Exposure:  Partial shade to full sun
• Characteristics:  Named "Ninebark" because it was originally believed to have 9 layers of shredding bark. Great species for streams, lakes, bogs and wet sites with other shrubs. White small flowers in terminal rounded clusters.       

Rosa pisocarpa

(Swamp Rose, Cluster Rose)

• Mature Height: 3'-6'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics: Perfect for wet sites. Has several clustered flowers versus individuals.

Sambucus racemosa

• Mature height: 10'-20'
• Moisture: Wet to moist
• Exposure:  Shade to full sun
• Characteristics: Berries are inedible unlike blue/black Elderberry. Great option for riparian sites, tolerates a variety of soils, soft pithy twigs. 

Ribes sanguineum

• Mature Height: 5'-10'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Young bark is fairly hairy, Clusters of white to red colored flowers which bloom early. Blue-black round berries which are edible but unpalatable. Likes dry open woods, rocky slopes, disturbed sites and is great for landscaping and wildlife browse. 

Cornus sericea

• Mature Height: 15'-20'
• Moisture: Wet to Moist
• Exposure: Partial shade to sun
• Characteristics: Commonly used in riparian zones. Forms beneficial thickets. Freely spreading with many stems. White to green flowers. White and blue tinged berry-like fruits important in winter for moose, deer and elk. 

Ceanothus sanguineus

• Mature height: 4'-6'
• Moisture: Moist to dry, well drained
• Exposure: Full sun 
• Characteristics: Drought tolerant and fire resistant. New twigs have a spicy flavor. White, fluffy, fragrant flower clusters. Likes dry fairly open sites, road margins, dry forest openings and edges. Common following fire. 

Shepherdia canadensis

(Soopolallie, Soapberry, Canadian Buffaloberry)

• Mature Height: 4'-6'
• Moisture: Moist to dry
• Exposure: Full sun to partial shade
• Characteristics: Predominately found east of the Cascades but can be found in isolated patches on the San Juan Islands and Olympic Peninsula. Yellow-brown flowers with males and females on separate shrubs. Bright red, translucent oval berries which are edible but very bitter and soapy to the touch. Found in dry to moist open woods and thickets. 

Rubus spectablis

• Mature Height: 10'-12'
• Moisture: Wet to dry
• Exposure: Shade to full sun 
• Characteristics: Highly adaptable species for riparian and upland plantings. Likes moist to wet sites, disturbed sites, stream edges, avalanche tracks, wet logged areas and forms extensive clones. Tasty, edible berries.

Amelanchier alnifolia

(Saskatoon)

• Mature Height: 6'-15'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Versatile shrub which spreads by rhizomes. Large white flowers, dull-red to black fruits with miniature edible apples. Likes roadsides, meadows, thickets and provides winter browse for birds and deer.

Garrya elliptica

• Mature Height: 10'-15'
• Moisture: moist, well-drained
• Exposure: Part shade to full sun 
• Characteristics: Beautiful, persisting white tassel flowers, evergreen leaves. Common on the coast. 

Shepherdia argentea

(Bullberry)

• Mature Height: 3'-4'
• Moisture: Moist to dry
• Exposure: Full sun 
• Characteristics: Deciduous shrub, pale yellow flowers with sepals but no petals. Bright red fruit which is edible but bitter. Provides foliage for birds, deer and small animals. Creates good thickets. Tolerates alkaline, drought and cold conditions.  

Symphoricarpos albus

• Mature Height: 3'-8'
• Moisture: Moist, well drained
• Exposure: Part Shade to full sun 
• Characteristics: Highly adaptable shrub. Clusters of poisonous white berries which last through winter. Pink to white bell-shaped flowers. Likes open forests, thickets, river terraces, ravines and along beaches. 

Ceanothus velutinus

• Mature Height: 3'-9'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Sprawling evergreen shrub. Spicy scented, forms thickets. White, small clustered flowers along the length of side branches are favored by butterflies. Likes open habitat, sunny locations and does well following fire. 

Mahonia aquifolium

• Mature Height: 3'-10'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Broad-leaf evergreen shrub with bright yellow flowers. Five to nine leaflets per leaf and one central vein in the leaflet. Likes drier, open and rocky sites.  When planting as bareroot, it is advised to defoliate the first year so the new buds will set. 

Rubus parviflorus

• Mature Height: 4'-10'
• Moisture: Moist to dry
• Exposure: Full shade to full sun 
• Characteristics: Forms dense thickets. White, large petaled, crinkled flowers. Shallow-domed red clusters of edible berries. Likes open sites, clearings, non-dense Red Alder forest and low elevations. 

Rubus ursinus

• Mature Height: 1'-2'
• Moisture: Moist to dry, well drained
• Exposure: Full shade to full sun 
• Characteristics: Evergreen trailing and climbing shrub, trailing to 5+ meters. White or pink large flowers. Black blackberries, edible and tasty. Likes disturbed sites, thickets and dry open forest. Tolerates some salt spray in shoreline habitats. Good option for erosion control.

Lonicera involucrata

• Mature Height: 5'-10'
• Moisture: Moist to wet
• Exposure: Part shade to full sun 
• Characteristics: Yellow, tubular twin flowers which produce shiny black twin berries all summer. Berries are great for birds but not palatable to humans. Likes moist forest, clearings, stream side habitats, swamps and thickets. Tolerates some salt spray in shoreline habitats. Fast growing and a good option for erosion control.

Rosa woodsii

• Mature Height: 3'-6'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Many branched native rose, predominantly found East of the Cascade Mountains. Forms dense thickets. Red, prickled stems, pink, 5-petaled flowers, followed by orange hips. Likes open woods, plains, stream banks, sandy or light clay soils. Has special value to bumble bees for nesting material.

Acer macrophylum

• Mature Height: 65'-100'
• Moisture: Moist to dry
• Exposure: Partial Shade
• Characteristics: Large, majestic multi-stemmed habitat and shade tree. Opposite, deciduous, 5-lobed maple leaves, winged seeds 3-6 cm long. Likes dry to moist sites, often near Douglas Fir and/or on sites disturbed by fire, clearing or logging. Carries high amounts of mosses. Stumps sprout vigorously after cutting or fire. 

Prunus emarginata

• Mature Height: 25'-30'
• Moisture:  Moist to dry, well drained
• Exposure: Partial shade to full sun 
• Characteristics: Great under story species in moist woodland, along streams or as a pioneering species in open disturbed/logged areas. White/pink flowers with bright red, inedible 1 cm cherries. 

Populus balsamifera ssp trichocarpa

• Mature Height: 100'-150'
• Moisture: Wet to moist
• Exposure: Partial Shade
• Characteristics: A wonderful restoration species with aggressive roots which help prevent stream bank erosion. Buds are sticky and full of resin that bees like to collect. Enjoys wet to moist areas, islands floodplains and major rivers. 

Crataegus douglasii

• Mature Height: 12'-30'
• Moisture: Moist - dry
• Exposure: Part shade - full sun
• Characteristics: Great for moist forest edges, coastal bluffs, thickets, shorelines, riparian areas, roadsides and upland areas as a soil and stream bank stabilizer. Black-purple "apples" are edible and have large seeds. Great strength wood with a fine grain

Rhamnus purshiana

• Mature Height: 30'-45'
• Moisture: Moist to dry
• Exposure: Part shade to full sun
• Characteristics: Attractive to wildlife. Wonderful for restoration sites and home landscapes. Green-yellow flowers in small, umbrella shaped clusters. Blue-black to purple edible berries. Likes shade and does well in mixed woods with conifers, swamps, Red Alder and Vine maple. 

Prunus virginiana

• Mature Height: 20'-25'
• Moisture: Moist to dry
• Exposure: Part shade to full sun
• Characteristics: Suitable for a wide range of habitats, from riparian areas to dry upland sites, forest edges and clearings. Similar to Bitter Cherry, but with differing flowers and fruits, which are in clusters of more than ten. Purple-black fruits.

  Alnus incana

• Mature Height: 45'-70'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun
• Characteristics: Alnus incana is named for its smooth grey bark. A hardy tree that is tolerant of poor soils. Particularly fast growing in full light and wet soils.

Fraxinus latifolia

• Mature height: 60'-80'
• Moisture: Wet to moist
• Exposure: Partial Shade to full sun
• Characteristics: Great for restoration sites which flood seasonally. Small inconspicuous flowers: males, yellow and females, green. Winged fruits in large clusters. Likes moist soils in low elevations, streams or flooded areas. Wood is tough and good for furniture. 

Quercus garryana

(Garry Oak)

• Mature Height: 60'-80'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Provides excellent wildlife habitat. Tiny flowers and acorns in shallow, rough cups. Likes dry rocky slopes, bluffs and well-drained soilg

Malus fusca

• Mature Height: 20'-40'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics: Important habitat species. Likes moist foods, swamps, low and damp sites, stream sides, standing and flowing water and estuaries. White and/or pink flowers, fragrant apple blossoms with edible egg-shaped apples. 

Cornus nuttallii

(Western flowering Dogwood)

• Mature Height: 50'-65'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Beautiful white, clustered flowers and bright red berry fruits which yield seeds for birds and other wildlife. Likes moist, well drained areas, streams and gullies. 

Betula papyrifera

(White Birch)

• Mature Height: 80'-100'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics: Great for restoration sites, white papery bark, nutlet fruits with wings, likes woods, moist bogs and wetlands. Can be distinguished from similar-looking Bitter Cherry by pointy tipped leaves.

Populus tremuloides

• Mature Height: 50'-80'
• Moisture: Moist, well drained
• Exposure: Partial shade to full sun 
• Characteristics: Great for landscapes and riparian areas. A smaller great alternative for cottonwood. Flat leaf stalks which tremble. 

Alnus Rubra

• Mature Height: 60'-80'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun 
• Characteristics: Attracts patches of lichens, hanging cylindrical spiked flowers, clusters of brown cones. Likes moist woods, stream banks and recently cleared land. Aggressive, fast-growing, great for grasses, sedges and ferns, nitrogen fixing. Makes a great riparian and timber species but should not be placed near blueberry or salal

Acer glabrum

(Douglas Maple)

• Mature Height: 10'-30'
• Moisture: Moist to dry
• Exposure: Partial shade to full sun 
• Characteristics: Small tree, one large wing fruit with pairs attached in "V." Does well as an under story species, very sunny exposed ridges, avalanche tracks and does better on more open sites than Vine Maple. 

Alnus sinuata

• Mature Height: 10'-30'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun 
• Characteristics: Valuable for slope and stream bank stabilization. Has small nutlets with broad wings. Likes edges of wet meadows, shorelines and is snow resistant. 

Acer circinatum

• Mature Height: 15'-25'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun 
• Characteristics: Suitable for riparian, forest and upland sites. Branches root and form new colonies. White flowers in clusters. Winged fruits with widely spreading pairs almost in a straight line. Does well under other tree canopy, forest edges, clear-outs and lava flows.

Betula occidentalis

• Mature Height:  20'-35'
• Moisture: Moist to wet
• Exposure:  Sun to partial shade
• Characteristics:  A deciduous small tree that can grow in thickets of spreading branches and broad open crowns.  Often occurring in riparian wetland habitats along streams and lakes within mixed conifer forests.

Alnus rhombifolia

• Mature Height: 50'-80'
• Moisture: Moist
• Exposure: Part shade to full sun 
• Characteristics: Fragrant, shade tolerant, makes a great riparian tree on edges of standing or flowing water.

Pseudotsuga menziesii

• Mature Height: 200'
• Moisture: Moist to dry, well drained
• Exposure: Part shade to full sun 
• Characteristics: Flat needles, sharp pointed buds, small brown pollen cones. Important timber species and great for upland restoration, dry low elevation to moist montane sites. Establishes well after fires on wetter sites.

Abies grandis

• Mature Height: 150'-300'
• Moisture: Moist to dry
• Exposure: Part shade to full sun 
• Characteristics: An excellent restoration and timber species, does well in dry to moist rainshadow areas. Makes an excellent understory tree for Douglas Fir. Sensitive to fire because of its thin bark. 

Calocedrus decurrens

• Mature height: 100'-150'
• Moisture: Moist to dry, well drained
• Exposure: Partial shade to full sun 
• Characteristics: Does not tolerate deep shade. A great choice for a privacy screen or windbreak. Thrives on dry sites in low to middle elevations. Can be distinguished from W. Red Cedar by its 6-scaled seed cones versus 8-12.

Abies procera

• Mature Height: 90'-200'
• Moisture: Moist, well drained
• Exposure: Part shade to full sun 
• Characteristics: Tall, symmetrical and conical in shape. Grows on all landforms, upper and middle elevation, from rugged slopes to valley bottoms, but stands are better suited to gentle terrain. 

Pinus ponderosa

• Mature Height: 80'-100'
• Moisture: Moist to dry, well drained 
• Exposure: Full sun 
• Characteristics: Drought tolerant, will tolerate some shade. Also called "yellow pine", a great restoration, conservation and timber species. Likes inland sites which are dry and open. Bark smells like vanilla in heat.

Chamaecyparis lawsoniana

• Mature Height: 100'-180'
• Moisture: Moist to dry, well drained
• Exposure: Full sun, but shade tolerant
• Characteristics: Susceptible to root rot in excessively wet soil. In open exposure, branches and foliage will remain full almost to the ground. Evergreen and adapted to humidity. Aside from fungus, the species is relatively free of disease and insect problems. 

Pinus contorta contorta

• Mature Height: 10'-60'
• Moisture: Wet to dry
• Exposure: Shade to full sun 
• Characteristics: Irregular pillowy crown, moderately thick bark, highly adaptable, tolerant of low nutrients, dunes, bogs, rocky hilltops and salt spray. Often the only tree species on very difficult sites and can assume a dwarf bonsai form.

Picea sitchensis

• Mature Height: 100'-150'
• Moisture: Wet to moist
• Exposure: Part shade to full sun 
• Characteristics: Stiff, very sharp needles which can hurt to the touch. Likes moist, well drained floodplains, headlands, recent glacial out-wash, old logs and mounds. Often paired with Western Red Cedar on sites as a brouse deterrent. Can hybridize with White Spruce.

Tsuga heterophylla

• Mature Height: 140'-180'
• Moisture: Moist, well drained
• Exposure:  Shade to full sun
• Characteristics: Great habitat, restoration and timber species. Pollen cones are small and numerous. Does well on dry to wet sites and is well adapted to growing on decaying wood, mineral soil. Provides a dense canopy which few under-story plants can grow underneath. Needs significant organic content in soil.

Larix occidentalis

• Mature Height: 100'-150'
• Moisture: Moist to dry, well drained 
• Exposure: Part shade to full sun 
• Characteristics: Excellent timber and restoration species. Cone covered branches are attractive in winter. Often follows or survives fires. Likes valleys, mountains and swampy areas. 

Thuja plicata

• Mature Height: 150'-200'
• Moisture: Wet to moist
• Exposure: Shade to full sun 
• Characteristics: Branches droop but swerve upward in a "J." Bark tears off in aromatic strips. Likes wet to moist soils, shaded forests, bogs, forested swamps, riparian areas and drier upland sites. It will out compete Yellow Cedar on common sites. 

Pinus monticola 

• Mature Height: 150'-200'
• Moisture: Moist to dry, well drained
• Exposure: Partial shade to full sun 
• Characteristics: The scientific name, pinus monticola, means "inhabiting mountains." It is blister rust resistant, medium sized and symmetrical. Likes moist valleys, open and dry slopes.

Populus balsamifera ssp trichocarpa

• Mature Height: 100'-150'
• Moisture: Wet to moist
• Exposure: Partial shade
• Characteristics: Aggressive roots to prevent stream bank erosion, likes low to mid elevation, has oval leaves with a round heart shaped base and seeds covered in fluffy, white hairs. 

Salix exigua

(Narrowleaf willow)

• Mature Height: 6'-20'
• Moisture: Moist
• Exposure: Partial shade to full sun
• Characteristics: Likes low to mid elevations. Gray-green lance shaped leaves. Can spread by underground stems. Clumping deciduous shrub/tree. Great for diversity, bank stabilization, increase in water quality, benefits to fish and wildlife habitat. Utilized in ditches, sandbars, wet sandy gravels for conservation biological control. 

Salix drummondiana

• Mature Height: 6'-15'
• Moisture: Moist
• Exposure: Part shade to full sun 
• Characteristics: Likes lower to mid elevations. Highly adaptive with sufficient moisture in soils. Likes moist mountain habitats, forest, riverbanks and floodplains. Brittle branches, but excellent for wildlife cover and browse in riparian areas. Provides winter wildlife food and dam material for beavers.

Salix hookeriana 

• Mature Height: 10'-18'
• Moisture: Wet to moist 
• Exposure: Partial shade to full sun
• Characteristics: Can handle marine environments and salt spray. Likes low elevations, wet sites, edges of standing water, sandy beaches and dunes. Has hairy egg-shaped leaves. 

Salix mackenzieana, Salix prolixa

• Mature Height: 8'-12'
• Moisture: Moist
• Exposure: Partial shade to full sun 
• Characteristics: Slender trunk with narrow crown, likes wet soils of stream borders and swamps. Can handle rocky river edges and terraces as a pioneer species. Valued by bumble bees and honey bees.

Physocarpus capitatus

• Mature Height: 10-15'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun
• Characteristics: Great for streams, lakes, bogs and wet sites.

Salix lucida ssp lasiandra

• Mature Height: 30'-36'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun
• Characteristics: Lance-shaped leaves with pale yellow bracts. Likes sea-level to mid elevations. Used in riparian buffers to help reduce erosion, protect aquatic environments and increase biodiversity. Likes riverbanks, floodplains, lakeshores, wet meadows, shallow backwaters and is highly adaptable. 

Salix ammygdaloides

• Mature Height: 25'-30'
• Moisture: Wet to dry
• Exposure: Partial shade to full sun
• Characteristics: Pale yellow-green fine toothed arrow leaves, weeping branches. Protects riverbanks from erosion. Does well in low, wet open woods, edges of streams, ponds, roadside gullies and prairie sloughs. Fast growing. Attracts butterflies and bees.

Cornus sericea

• Mature Height: 15'-20'
• Moisture: Wet to moist
• Exposure: Partial shade
• Characteristics: Creates beneficial thickets, great for riparian areas. Likes valley bottoms and mid-elevations. Oval leaves when young, sharp and pointed when older. White to green flowers.

Salix scouleriana

• Mature Height: 15'-20'
• Moisture: Wet to dry
• Exposure: Partial shade to full sun 
• Characteristics: Tall, spindly shrub, branches dark brown to yellow, creates great upland thickets. Readily colonizes after fire. Does well in stream side areas, clearings, edges of forests, wetlands and open forests. 

Salix sitchensis

• Mature Height: 15'-25'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun
• Characteristics: Likes wet sites to forest edges in low to middle elevations. Handles drier sites better than most willows. Silky capsule fruits. Grows rapidly and is great for restoration. Likes stream side thickets, lake shores, wetland margins, forest edges, wet openings, clearings and avalanche tracks. 

Lonicera involucrata

• Mature Height: 5'-10'
• Moisture: Wet to moist
• Exposure: Partial shade to full sun
• Characteristics: Excellent riparian and wildlife browse shrub. Small yellow twin flowers continually produce berries for birds all summer.