Wednesday, May 27, 2009

What To Grow - Shrubs, Part 2

Ceanothus thyrsiflorus / BLUEBLOSSOM

Large evergreen shrub or small tree to 10-20 ft. tall. Flaring crown of small, narrow, shiny leaves is covered in fuzzy flower clusters in various shades of blue in spring. Stunning in bloom, when it is buzzing with bees and butterflies. Needs sun and good drainage; may be frost-bitten in coldest areas. Very fast growing.

Cornus stolonifera (C. sericea) / REDTWIG DOGWOOD

Found in wet places from coast to coast, this large deciduous shrub grows fine in average soil. It is most acclaimed for its red twigs, which show off in winter. The leaves color well in fall ; puffy white flowers and white berries give interest most of the other months. Suckering and thicket-forming habit may rule it out of smaller places.

Garrya elliptica / COAST SILKTASSLE

Large evergreen shrub to 10 ft. or more. Thick, rounded, wavy-edged leaves give a nice texture. Silvery-green flower tassles, 6 in. or longer, hang like icicles in winter. Female plants bear purple fruits. Best in sharp drainage, full sun; leaves may be spotted with fungus in damp shade. The hybrid G. x issaquahensis is very similar and usually more adaptable.

Gaultheria shallon / SALAL

Evergreen understory through countless acres of Northwest forest. Rounded leaves make dense tangles, eventually to 6 ft. tall. Small, charming pink and white flowers lead to edible blue-black berries. Favors shady places, competing well with tree roots, but is adaptable to bright light. New plantings slow to establish; plant extras to make up for casualties.

Ledum glandulosum / TRAPPER'S TEA

Evergreen shrub 3-4 ft. tall, related to rhododendron. Narrow, delightfully aromatic, 2 in. leaves and clusters of tiny white flowers. Found in bogs, but adaptable to average soils. Easy to grow, hard to find.

Rhododendron macrophyllum / COAST RHODODENDRON

This large evergreen shrub is a regional symbol, though it is well outnumbered in gardens by hybrids. The native carries tight clusters of rose pink flowers, sometimes darker, rarely white, in May. All larger-leaved rhododendrons prefer part or full shade.

Rhododendron occidentale / WESTERN AZALEA

Large deciduous shrub 6 - 10 ft. tall. Beautiful white or creamy flowers, variously tinted or marked pink and gold, very fragrant, May into summer. Narrow, glossy leaves color red and yellow in fall. From wet places, but drought hardy, especially in light shade.

Spiraea densiflora / MOUNTAIN HARDHACK

Hikers admire this low, rounded mountain shrub for its attractive bluish foliage and fuzzy buttons of deep rose flowers in summer. Fall color is a blend of yellow, orange and purple. Grows 2-3 ft. tall and as wide; best in sun and moist soil.

Wednesday, May 20, 2009

What to Grow - Shrubs, Part 1


There are lots of these, so they will appear in several posts. I've tried to avoid the most unmanageable kinds - hardhack (Spiraea douglasii) and salmonberry (Rubus spectabilis) are two that take over the garden. Others, while beautiful, are too demanding to be listed here - the stink currant (Ribes bracteosum), which needs constant shade and moisture, comes to mind.

Holodiscus discolor / OCEAN SPRAY

Large deciduous shrub of drier slopes and roadsides. Small leaves beautifully scalloped and veined. Large, arching plumes of frothy creamy white flowers in summer make quite a show. Needs lots of room and an evergreen background to make up for its drab winter twiggery.

Lonicera ciliosa / ORANGE HONEYSUCKLE

Showy deciduous climber reaching 10-20 ft. into branches of trees. Round, bluish leaves contrast strikingly with clusters of vibrant orange flowers in late spring. Closely adapted to our dry-summer climate, this plant leafs out as early as February and by late August is withered. Attracts hummingbirds.

Lonicera hispidula / PINK HONEYSUCKLE

Evergreen climber usually seen with madrone on dry slopes. Small, roundish, gray-green leaves and pink flowers make a nice combination on sunny banks. Plants grow 10-20 ft. long, either up of sideways. Red fruit showy in winter.

Mahonia aquifolium / TALL OREGON GRAPE

Long a landscape staple, this tough evergreen bears prickly, shiny, divided leaves on many upright stems, usually to 6 ft. or so, sometimes much taller. Yellow flower clusters in March become blue fruits that, with enough sugar, have a pleasant, grapelike flavor. This species needs sun; it can mildew on heavy soils.

Mahonia nervosa / LOW OREGON GRAPE

This handsome evergreen carpets the floor of countless acres of Northwest forest. Large leaves divided into shiny, toothed leaflets are grouped atop 1-2 ft. stems. Sprays of yellow flowers in March lead to powder blue fruit. Best in shade, but adaptable.

Myrica californica / PACIFIC WAX MYRTLE

Large evergreen shrub or small tree, to 35 ft. in the wild, usually 10-15 ft. in landscapes. Narrow, bright green, aromatic leaves give it a full, lush look. Small gray, waxy berries in winter. Native only to the ocean shoreline, but widely planted as a 'native', good in sun or part shade, almost any soil.

Oemleria cerasiformis / OSOBERRY

Plain and often unnoticed, this large deciduous shrub brings an early breath of spring with emerging leaves and white flowers in February. Pea-sized 'plums' ripen from apricot to blue black. Best in the lightly shaded background.

Ribes sanguineum / FLOWERING CURRANT
A garden favorite in Europe for a century, this beautiful deciduous shrub is now welcomed into Northwest landscapes. Leathery, lobed, aromatic leaves cover its upright, 8 ft. form. From February through April, dangling clusters of pink to garnet red flowers make a stunning show. There are many cultivars, some in delicate pink or white. Best in light shade.

Rosa nutkana / NOOTKA ROSE

Showiest of our four native roses, with 2 in. fragrant pink flowers in May-June. Large red hips showy in fall. Makes a 6-8 ft. high thicket, and often too invasive in smaller gardens.

Symphoricarpos albus / SNOWBERRY

Known for its clouds of white berries in winter, the snowberry is also a valuable slope holder. Forms wide, 6-8 ft. tall thickets of wiry branches lined with small, rounded light green to bluish leaves. Tiny pink flowers open spring and summer. Grows in moist or dry soil, sun or shade, though shaded plants often mildew.


Evergreen shrub 6-10 ft. tall in the wild, smaller in gardens. Glossy, oval, 1 in. leaves emerge coppery red. Pink flowers open February to June, with tiny, luscious, blue to black berries from summer to winter. A choice ornamental for light shade and well-drained soil.

Monday, May 18, 2009

NW Natives: What to grow -Trees

Even when you think of native plants as you would plants from anywhere else- easy to grow, attractive in the landscape, and available in nurseries- the list of candidates is long. What follows is a brief description of over fifty native plants from Washington and Oregon suitable for landscapes west of the Cascades. Anyone interested in natives can think of others, but most of the really useful ones are here.


No giants here, just small to moderate species suitable for urban landscapes. Also missing are our two prettiest- madrone and Pacific dogwood- which usually do fine in just the right environment but are hardly easy.

Acer circinatum / VINE MAPLE
Multi-stemmed, to 20-30 ft. tall. Beautiful form, dazzling fall color. Rounded leaves shallowly divided into 7-11 lobes. Snaky, pale green stems give winter interest. Red flowers, seeds are showy. Best in part shade, where it is drought hardy; foliage may burn in hot sun without water.

Acer glabrum / DOUGLAS MAPLE
Like vine maple, or sometimes single stemmed, 40-60 ft. tall. Leaves deeply three-lobed, sometimes divided. Twigs and leafstalks red. Bright fall color. Sun or shade, good drainage. Hard to find in nurseries.

Betula papyrifera v commutata / NORTHWEST PAPER BIRCH
Slender tree to 60 - 80 ft. tall, with creamy, pink or rusty, peeling trunk. Yellow fall color. Likes moist soil, but tolerates drought. This local variety is rare in nurseries.

Calocedrus decurrens / INCENSE CEDAR
Very slender tree to 80 ft. tall with bright green foliage in lacy sprays. Good tall screen or accent, growing well on moist or dry soils. Slow growing in heavy clay.

Shrub or small tree to 25 ft. tall, with flaking bark. White flowers lead to gold fruit, edible but tiny. Toothed and lobed leaves give bright fall color. Native to wetlands, but fine on average soils. Scarce in nurseries; branches sometimes spiny.

Pinus contorta / SHORE PINE
Narrow, pyramidal tree with short, dark green needles on billowy branches. Picturesque form in age. Takes wet or dry soils. Attractive, useful, adaptable and commonly planted.

Populus tremuloides / QUAKING ASPEN
Slender tree to 60 ft. with pale bark, fluttering rounded leaves, gold fall color. Bark is seldom as white west of the Cascades as it is in the interior, but still nice. Best where moist; attracts aphids when dry. Suckering can be a nuisance.

Quercus chrysolepis / CANYON LIVE OAK
Evergreen tree to 60 ft. with small, shiny, holly-like leaves on beautifully gnarled limbs. Fast growing if given occasional summer watering, but very drought-hardy. Fine climbing tree, but fallen leaves are prickly. Hard to find.

Quercus garryana / OREGON WHITE OAK
Rounded deciduous tree to 80 ft. tall. Dark, lobed leaves on gnarled branches make an open crown. Slow growing, but speeds up if watered in spring and early summer (but old, established trees should never be watered).Uncommon in nurseries; requires good drainage.

Sambucus caerulea / BLUE ELDERBERRY

A small tree, to 20-30 ft., often shrubby. It is scarce, but not for lack of showy beauty. Large, compound leaves give a tropical luxuriance to its spreading crown. Showy, flat, 8-12 in. clusters of tiny cream flowers lead to even showier clusters of powder blue fruits that bend the branches in late summer. These are sweet and good if cooked. Sadly, hard to propagate and thus hard to find.

Tsuga mertensiana / MOUNTAIN HEMLOCK
Picturesque, narrow tree to 20-30 ft. tall. Sharp, angular branches clothed in blue-gray needles. A high-elevation species surprisingly at home in lowlands. Needs sun, decent drainage.

Umbellularia californica / OREGON MYRTLE, CALIFORNIA BAY
Rounded evergreen tree 40-80 ft. tall, with shiny, aromatic leaves. Beautiful bright green canopy casts heavy shade. Takes moist or dry conditions. Often creates a 'family' of seedlings around the neighborhood.

Xanthocyparis (Chamaecyparis) nootkatensis / ALASKA YELLOW CEDAR
Gracefully drooping branches give this mountain native great drama. Slow growing to 50-70 ft., fairly narrow except for a few wider branches. Takes wet or dry soil.

Next time: Shrubs

Wednesday, May 13, 2009

Knowing Northwest Natives

The stampede to native plantings is a good thing overall, but there are misconceptions about how to use native plants and what to expect from them. Some people adore all native plants simply because they are ours; others dismiss them as so much brush. Many people would never buy what they could supposedly drive into the countryside and dig up. Let's look at the facts.

A native plant is a species that has grown wild in your climatic region since before settlement. With a tremendous variety of climate and terrain, the states of Washington and Oregon have many natural zones and well over 3,000 native plants. Species from high mountains may not grow in low elevation gardens; those of the sagebrush deserts may rot if planted on the coast.

Similarly, each zone has various habitats- wetlands, dry bluffs, alluvial valleys, north and south exposures- and most plants have strong preferences. It is dangerous to assume all native plants are drought-hardy, though many are quite adaptable.

Nor are native plants all easy to grow. Many Northwest natives, even common ones, are challenging to propagate and establish. Plantings of salal (Gaultheria shallon) are usually riddled with casualties. Low Oregon grape (Mahonia nervosa) and blue elderberry (Sambucus caerulea) are notoriously difficult to propagate, as are most of the lily family. Native plants fall victim to pests and diseases just as much as most introduced plants. Deer, especially, are fondest of the plants they know.

Then there is lack of selection. While we have a large flora because of climatic diversity, in any one area the variety of native plants is low and, for many of the reasons above, some of the plants we have are impractical for landscape use. We have almost no trees suitable for streetside or patio, few showy flowering shrubs, few evergreen screen plants. Most of our conifers are too towering for smaller landscapes.

But the good of natives outweighs the bad. First, they simply belong here. Native plants should always be considered first as candidates for any landscape role. If a native plant makes sense, it should be used.

How sensible any plant choice is depends on the situation. For rough and wild areas, natives are a must. Closer to civilization, the matter is more complicated. Considerations of wildlife value and native purity may clash with the desire for showy flowers, fragrance and architectural forms that may not be offered by any native plants. Most successful plantings manage to combine native and non-native just fine. Some beautiful gardens are made of Northwest natives alone.

Next time, I'll try to make a list of the most useful Northwest native plants for gardens and commercial landscapes.