Monday, June 25, 2012

From Our Garden- June 2012

Our new garden is filling up fast. Even this generous space won't be enough to hold all the plants we find interesting and worth propagating.

The garden is in a fortunate location- sunnier and milder than most of Seattle, with well drained soil and a variety of sun exposures. Nearly any plant will be happy here somewhere.

The harsh winter of 2010-2011 eliminated a few of our brand-new plantings, but most survived and hundreds have joined them since then. The most remarkable survivor of the cold, just now showing new fronds after 18 months, is the Chilean wine palm (Jubaea chilensis). Years from now (mild years, we hope), this will be a massive, feathery landmark.

From a different direction completely, yet happy here so far, are the Himalayan blue poppies. These have no trouble with our odd cold spells but they hate sun and dry heat. In their bed just north of the house- bright but shaded, well drained but faithfully watered- they have been beautiful. The first to bloom was actually not blue but creamy lemon. Meconopsis integrifolia will, alas, probably not return, since it dies after flowering, but it was glorious. M. x sheldonii, a reliable perennial, was next. Flowers the color of an Arizona sky made an amazing display that just overlapped M. baileyi, which is still clustered with crinkly amethyst blue flowers.

Sun roses (Helianthemum), native iris (Iris douglasiana), potentillas, and euphorbias flow into one another in the sunny front slope, nearly swamping slower growing agaves, Hesperaloe, yuccas and heathers. The colors are abundant and sometimes surprising.

For plants from moist but sunny settings, we have a 'swamp circle'. Watered daily, this bed holds mints, astilbes, native asters, colorful sedges and irises, all looked over by an Aralia elata 'Aureovariegata', with huge divided leaves of soft green and cream.

The show-off in this bed right now is a Louisiana iris we have identified as 'Black Gamecock'. It's velvety blackberry colored falls are painted with a narrow streak of electric gold. These evergreen irises, though thirsty, deserve to be tried here more often.

Nearby, but happily dry on its rock ledge, Dianthus freynii makes a fragrant mound of small pinks. The dense cushion of blue leaves is almost prickly, with a metallic glow, especially in winter. This native of southeast Europe will eventually upholster all the rocks below it.

Along the same rock ledge, Penstemon heterophyllus is showing off in gleaming clear blue. This cultivar, 'Electric Blue' is well named and will look great for several months. The species, a mounded evergreen shrublet, comes from California.

The tea tree, or manuka, is looking great right now. This heather-like large shrub from New Zealand and Australia is not only pretty, but loaded with vitamin C. When Captain Cook arrived in Australia with a crew dying of scurvy, the native people made a tea of Leptospermum scoparium and saved everyone. In gardens, it makes an airy evergreen to 8 ft. tall, well sprinkled in white flowers in late spring. And the tiny leaves, smelling of eucalyptus, really are nice in tea.

 amazing show for six weeks, just overlapping with M. baileyi, which is still clustered with traslucent, crepe flowers in amethyst blue.  

Friday, May 7, 2010

Plants We Like

At Colvos Creek Nursery, we grow anything interesting. Our mild climate (last year's 103 degree heat wave sandwiched between two record cold waves notwithstanding!) allows huge opportunities. Northwest natives are a priority and many of those fit into our second area of interest, rare plants.

Last fall we collected and sent for a great volume of propagating material to replenish and re-invigorate a selection of plants that had dropped off along with the economy. Now many fine plants are ready or will be shortly.

From Chile comes the surprisingly hardy blue abutilon (Abutilon vitifolium). A somewhat treelike evergreen shrub to 10 ft. or so, it is covered in the maple-like foliage common in the genus, though here grayish and fuzzy. In spring, and sometimes fall, come the 3 inch saucers of lilac blue, stopping people in amazement. Also amazing is how hardy this exotic beauty is- to Zone 7- and it is has survived on Long Island.

The red buckeye (Aesculus pavia) is a delightful deciduous shrub from the eastern US. Its handsome, handlike ('digitate') leaves are like those of other species, scaled down. Indeed, the whole plant is scaled down to garden size, seldom more than 10 ft. by 10 ft. and easily kept narrower. The spikes of tomato red flowers, sometimes salmon pink, are an alluring spectacle in late spring, coming on stage after the flowery extravagance of March and April.

The Australian bottlebrushes are emblematic of that continent's strangely beautiful flora. For those in colder places who want to grow one, especially a red one, the best hope is what we call the hardy red bottlebrush (Callistemon subulatus). Temperatures of 10 degrees will hurt it substantially, but it will usually regrow and bloom the same year. Above 15 degrees it is safe. The narrow evergreen leaves, scented of eucalyptus, line arching branches that create a fountain shape. In summer, brilliant red brushes tip the branches and bring in hummingbirds as well as fascinated passersby.

Loquats are luscious orange fruits that most people have never heard of. The evergreen tree they grow on, Eriobotrya japonica, is equally luscious, carrying corrugated, foot-long leaves in heavy bunches. Even without the fruit, it is a standout ornamental. With luck, and especially with two or more trees, you can look forward to the egg-sized fruit, which has a taste combining peach and pineapple. The tiny white flowers open fall through spring, so frost may ruin them, but if the winter finishes mild, more flowers will open. In any case, the tree is best in Zones 8 and up.

Among Northwest natives, one of the most captivating, the madrone, Arbutus menziesii, is also one of the hardest to grow. Strictly adapted to our dry summers, it will die if watered, and it often suffers disease in urban areas. Still, its lush, evergreen foliage, fragrant white flowers, showy red berries and peeling red-orange bark on a sinuous framework make it an object of desire. Few nurseries grow it, for the reasons above, and they won't transplant from the wild. We seem to have the knack for starting them and have a good crop this year.

Early, fragrant flowers on a drought-tolerant small tree should put the flowering apricot on every gardener's want list, but Prunus mume has not made the horticultural hit parade. It can have problems with disease, but seldom when planted in a sunny, well drained spot. This is the tree that has lent its pink flowers and sweet scent to the many flowering plums. Those are fine, but this has real character, carrying its blooms on gnarled, spreading branches. The flowers, one of the primary subjects in Asian art, lead to the astringent yellow plums that are made into sauces and wine.

Penstemons abound in the Northwest, especially in mountains and deserts. Shrubby penstemon, P. fruticosus, is a mountain species, making evergreen carpets of narrow leaves on sloping scree. Short spikes of flowers in shades of rosy lilac and violet blue smother the plant in late spring, which may be July at the higher passes. Given sun and good drainage, this penstemon, unlike many wild species, takes well to gardens.

It surprises many people that there are evergreen oaks, let alone that most oaks are evergreen. As a group, they offer rugged year-round beauty in a variety of looks. The silverleaf oak, Quercus hypoleucoides from the southwest, carries a luxuriant crown of slender, willowy leaves designed to puzzle. Only the acorns prove it to be an oak. The silver comes from the velvety white undersides of the leaves, which flash artfully in the wind. In habitat, this oak receives copious moisture from summer monsoon rains, yet is very drought-hardy.

Among the deciduous oaks, none makes a grander impression than the daimyo (Quercus dentata) from Japan. The leaves are 12 inch, deeply scalloped paddles that give a tropical texture, carried on soaring and arching branches. Alas, there is only mild amber fall color, but the leaves drop to reveal great natural sculpture.

Brooms (the plants) have a bad reputation in the Northwest, where the yellow of the Scotch broom screams from nearly every vacant acre in late spring. The Atlas broom (Cytisus battandieri) is innocent, quite scarce in gardens and hardly recognizable as a broom. In most species, tiny, often short-lived leaves make the shrub a wispy mass of green twigs. The Atlas broom has real leaves, evergreen, with three 2 inch silvery leaflets. Orange-yellow flowers in tight conical clusters open in late spring with a fragrance of peaches and pineapple. To see one of these unique plants is to want one, and now, for once, we have a good crop.

Monday, October 26, 2009

Northwest Collecting Trip

Our nursery, Colvos Creek on Vashon Island near Seattle, specializes in variety. We try to carry as many Northwest natives as possible and any and all drought-hardy plants and rare and unusual species from all over the world. We can buy seeds from many sources, but others are not for sale and have to be gathered.

Our first collecting trip this fall was a circuit around southern Washington. The route took us over White Pass , just over 4000 feet, down into the arid Columbia Basin, south over Satus Pass at 3300 feet, back through the Columbia River Gorge and north again past Mt St Helens to rejoin the White Pass Highway. Over three days we gathered seeds and cuttings of over 90 species.

Anyone making this trek would be awed by the scenery and struck by the great variety of climate and vegetation. They would also stop thinking of the Northwest as all wet and mossy.

The Cascade Mountains divide Washington and Oregon into a rainy coastal side and a dry interior. Within two hours, the traveler passes from foothill rain forests with well over 100 inches of precipitation annually to sagebrush desert receiving less than 5 inches.

One of the most interesting places we visited was the Wapato National Wildlife Refuge, south of Yakima. The mix of riparian, desert and grassland is stunning.

After crossing the mountains south to Goldendale, we headed east across a lonely arid plateau with only a few large ranches. A canyon brought us down into groves of white alder, willow and ponderosa pine, then back up onto the plateau. After we turned south toward the Columbia River, we were met by scattered western juniper (Juniperus occidentalis), dark green gumdrops on a gray and tan backdrop. Towards the river, these became bigger and more abundant. Some of the largest, 60 feet tall and 3-4 feet across, could be 1000 years old.

We worked our way west along the dramatic cliffs at the eastern end of the Columbia River Gorge where the river persistently kept its course over two million years as the Cascade Mountains pushed up thousands of feet.

The next day we continued west through the gorge, which is one of the world's great natural landmarks. Here, the arid interior, hot in summer, cold in winter, collides with the moist mildness of the coast. At the midpoint, bluffs may have ferns and maples on one side, sage and cactus on the other.

Our route north from the gorge took us to over 4000 feet again, and past famous Mt. St. Helens. Collecting was very good, but we were up in the clouds most of the time. No views of the mountain and no good pictures.

Friday, July 3, 2009

Broadleaved Evergreen Trees- conclusion

Magnolia grandiflora / EVERGREEN MAGNOLIA

This one, at least, is common and perhaps overused, likely for want of other choices. It is certainly a dramatic beauty, with large, glossy leaves and huge, deliciously fragrant white flowers. There are many cultivars, most with intermediate foliage and pyramidal crowns 40-60 ft. tall. Dwarfs like 'Little Gem' are popular for restrained size, though this one sometimes has a problem with fungus that thins the foliage. "Majestic Beauty has the largest leaves, but can be pale and shy-flowering here. 'Bracken's Brown Beauty' and 'D. D. Blanchard' are dense and narrow , with striking rust-brown leaf undersides. Evergreen magnolia is amazingly hardy and adaptable, but trees on dry hardpan may be thin, yellowish and stunted.

Magnolia virginiana v australis/ EVERGREEN SWEET BAY

This harder-to-find magnolia may be a more useful tree in most situations. Smaller, narrower leaves than those of M. grandiflora, silvery below, give it a more intermediate texture. Small, fragrant white flowers open through the warmer months. Most trees reach a narrow 30 ft. or so. Though a swamp tree, it is remarkably drought-hardy. Cultivars such as 'Henry Hicks' are typically evergreen though they may not fall under variety australis. Best to buy M. virginiana in late winter to be sure of its leaf retention.

Maytenus boaria / CHILEAN MAYTEN

Willowy grace is the feature of this small tree. Narrow, 1-2 in. long leaves in bright green make billowy streamers arching from slender branches. Some plants are full and upright, others, especially when older, take on a weeping-willow habit. Mayten tolerates wet soil as well as drought, though it is very slow on dry hardpan. Trees in shade or moist soil may reach 40 ft. while those in tougher circumstances stay 15-20 ft.


As charming as its common name, this small magnolia relative ( now officially a Magnolia, it seems) grows to 20 ft. or so, with glossy, 4-6 in. leaves and large, fragrant white flowers in spring. It is relatively new and scarce in the Northwest, but established trees, seen here and there, have done well and the tree seems hardy in at least our warmer zones. A few street trees in Portland are thriving without water.

Nothofagus dombeyii / COIGUE

Most of the southern beeches, Nothofagus, are tiny-leaved evergreens. This Chilean species captivates nearly everyone with its deep green, 3/4 inch leaves in neat, flat fronds on slender, undulating branches. Young trees race to a height of 80 ft. or more, with many smooth, gray ascending branches. Old specimens in Chile resemble gnarled oaks. The only hangup with these trees, besides rarity in nurseries, is their vulnerability to high winds; a spot where the prevailing winds are filtered is best.

Persea yunnanensis

Related to avocado and other subtropical beauties out of our reach, this rare Chinese tree is hardy in all the warmer Northwest zones. Its lush, rounded crown in made of slender, glossy, aromatic leaves that are silver-blue beneath. Blue, olive-like fruits ripen in fall. The tree reaches 40 ft. or more, drought-hardy and happy in sun or shade.

Photinia serratifolia / CHINESE PHOTINIA
Popular in the 1950's and earlier, this handsome tree deserves a comeback. Its large, glossy leaves, open in February and March in glowing shades of golden orange and coppery red. White flowers in wide clusters follow. Dense and round-headed, Chinese photinia reaches 30-50 ft. tall. Once shunned for mildew, it is seldom troubled by it in sunny, unwatered sites. Its hybrid offspring, the ubiquitous P. x fraseri makes a good small tree, too, but is increasingly subject to disease.

Quercus / OAKS

Here is the largest group of broadleaved evergreen trees for this area. At least half of the 600 oak species are evergreen; only a few are readily available though many others are sold by specialty nurseries. Colvos Creek carries many in small sizes.

Quercus chrysolepis / CANYON LIVE OAK

This native of sw Oregon and California has small, holly-like leaves on rather gnarled branches. It reaches 60 ft. or more, with a beautiful framework of smooth, very climbable branches. Bushy when young, it requires some early pruning to establish a straight, clear trunk for urban situations.

Quercus hypoleucoides / SILVERLEAF OAK

From the Southwest and Mexico comes this beautiful and easy-to-grow oak. Slender, tapered leaves are leathery gray green above, velvety white below, very nice in the wind. A layered, pyramidal crown reaches 20-30 ft. rather quickly, eventually topping out at 50-60 ft. This great tree is quite adapted to the Northwest and is thriving, though still rare, around the region.

Quercus ilex / HOLLY OAK, HOLM OAK

This sturdy oak of the Mediterranean region is planted in mild zones around the world and is seen here and there on the streets of Portland and Seattle. Its variable leaves are small, oval to tapered, toothed or not, and deep gray green above, pale below. The crown of a holly oak is usually dense and the trees have sometimes been sheared into formal shapes. Eventually, the tree opens up some and takes on more character. It is very adaptable and drought hardy, but trees brought up from California trained to a stake often have slender, weak stems. Better to take a bushy specimen with stout trunk and gradually prune to the desired form.

Quercus laurifolia / LAUREL OAK

This is perhaps the best broadleaved evergreen tree for streets and other city uses. Its narrow, grass-green leaves on slender branches thin out in winter, letting in light yet retaining a leafy green aspect. It makes a broadly pyramidal crown to 60 ft. tall and adapts to nearly any soil, from wet to dry. Though a native of the South, it is perfectly hardy here.

Quercus myrinaefolia / BAMBOOLEAF OAK

Slow and dignified, this Japanese tree eventually reaches 40 ft. tall with round outline. Narrow, tapered leaves are glossy bright green above, silvery below, and point slightly downward in an elegant pattern. This oak responds beautifully to rich moist soil but manages well in most conditions and is drought hardy once established. Several related Japanese oaks, Q. glauca, Q. acuta, Q. gilva and Q. stenophylla are all good, too.

Quercus suber / CORK OAK

Bottle-stoppers and flooring are made from the bark of this Mediterranean tree. In deep ridges and furrows it covers a beautifully gnarled and angled trunk that carries billows of gray-green, holly-like leaves in an open, 40-80 ft. crown. This is a character tree, best as a specimen, hard to use on streets unless pre-trained to a straight trunk. It is hardy in all warmer Northwest zones.

Sycopsis sinensis

A small tree related to witch hazel, this rather plain plant is never the less pleasing and quite hardy. Narrowly ovate leaves in deep olive green hang gracefully from slender branches to form a not-too-dense, rounded crown. Tiny puffs of orange flowers in winter reward close inspection. Drought-hardy and nearly pest free, the sycopsis shouldn't be so rare. It slowly reaches 20 ft. or so.

Umbellularia californica / OREGON MYRTLE, CALIFORNIA BAY

A native of California and southwest Oregon, Oregon myrtle can be a large shrub on dry hillsides or more often a tree to 80 ft. or more with moisture and better soil. Foliage is similar to that of Laurus, the Mediterranean bay, but more tapered, a bit brighter green and much more wild in aroma. Tiny winter flowers are followed by green, inch-wide fruits with large seeds that sprout readily in the vicinity. This handsome tree needs lots of room -it's hard for many plants to grow in its pungent shade- and the tree can be stunted by clay hardpan.

Thursday, July 2, 2009

Broadleaved Evergreen Trees

I can't stay away from the topic of broadleaved evergreen trees. Deciduous trees are the default setting in the Northwest. Yet in places where there is little but pavement, cars, buildings and worse, we need the softening and color of foliage all the time. Though large expanses of deciduous forest or shrublands are lovely even in winter, a few trees along a downtown street or in a parking lot aren't enough to counteract the cold, gray harshness of an urban scene when they are leafless. We need foliage.

There are several arguments against broadleaved evergreen trees. The most reasonable one is that they block valuable winter sunlight. To avoid that, these trees should be kept away from windows, especially on the south, or trimmed high enough that the low winter sun reaches the window. Also, there are some evergreens with light canopies- laurel oak, for example- that let light through.

Others argue that broadleaved evergreens lose branches in our occasional heavy snows. It seems logical, but trudging through the extended snows of last December, I did not see an extraordinary number of leafy branches on the sidewalk and most broadleaved evergreen trees around here are no worse for wear. Those that had the most trouble with the snow had long, slender branches, especially loquats and magnolias. Pruning to shorten these limbs (which usually causes them to become stouter) can help.

Finally, there is the complaint that they aren't available. That's also somewhat true, especially if you need a large specimen. It's an extra cost to bring up trees from California or the South for a landscape project. If you can start smaller, several sources, including our nursery, Colvos Creek on Vashon Island, offer many broadleaved evergreen trees.

Here are some of the broadleaved evergreen trees suitable for Northwest landscapes:

Arbutus menziesii / MADRONE, MADRONA

One of our most alluring natives, this tree enchants with its peeling red-orange bark. Large, glossy leaves, fragrant white flowers and bright red fruits all on a beautifully sinuous framework add up to a stunning ornamental. Sadly, the tree is very hard to transplant, though it establishes fairly easily from nursery pots. Madrones need full sun and sharp drainage and can be killed by irrigation or fertlizer. Older trees have suffered in recent decades from various blights.

Arbutus 'Marina' / HYBRID MADRONE

This newcomer is a hybrid of mysterious origin. It has foliage smaller than madrone, and showy pink flowers in fall-winter (or almost any time). Some trees bear huge orange-red fruits like those of strawberry tree (A. unedo). Bark is reddish, flaking. A small tree to 20-40 ft., 'Marina' has become popular in the Northwest, especially on streets. It wants sun and good drainage and is a good bet only in the warmer parts of the region.

Azara microphylla / BOXLEAF AZARA

With tiny, glossy leaves on graceful, airy fronds, this Chilean beauty has many admirers. Its narrow outline and quick growth make it a great screen, even between buildings. Coming from forests, it is good in shade but takes sun well; it is quite drought hardy once settled. The frosting on this cake is the crop of puffy yellow flowers in February wafting a scent of chocolate and vanilla. The variegated form 'Variegata', with cream-edged leaves, is breathtaking.

Cornus / DOGWOOD

It surprises people to learn that there are evergreen dogwoods (and maples, pears, elms, ashes, etc.) These three really do stay green and are fine small trees for milder areas. All come from south and east Asia, where there is a swarm of related evergreen species.


This one stands out from the others because of its light green or grayish foliage and creamy yellow flowers. A small tree to 15-25 ft. tall, it sends its long branches artfully leaping and arching in all directions. These are covered in showy flowers that age strawberry pink over many weeks in late spring. Pink-red fruits, nearly golfball-sized, ripen in fall. Well worth a sheltered, partly shaded spot, this dogwood is hardier if raised from local seed, as ours are.

Cornus kousa v angustata / EVERGREEN KOUSA DOGWOOD

Most trees under this name are smaller, evergreen versions of the popular C. kousa. Their glossy leaves, silvery below, makes them fine foliage trees. That's good, because, so far, they have been shy flowering in the Northwest. The flowers they do produce are like those of the species, with creamy white, pointed bracts. Like the species, this variety is fairly drought-hardy.

Cornus omeiensis / MT OMEI DOGWOOD

Seen mostly in the cultivar 'Summer Passion', this dogwood is a dense, rather narrow tree to 10-15 ft. so far. New foliage, produced most of the year, is copper red. Like the dogwood above, it is also shy to make flowers, which are smaller versions of those of C. kousa. With or without flowers, this tree is a fine screen plant or small standard tree for sun or shade. It seems hardy in all but the coldest zones west of the Cascades.

Eriobotrya japonica / LOQUAT

A subtropical fruit tree with huge, leathery leaves seems an unlikely choice for the Northwest, but this Asian beauty is hardy in all the milder parts of the Puget-Willamette trough. There are trees 30 ft. tall in Portland and Seattle, and most specimens bear luscious orange fruit. Even without fruit, the foot-long, corrugated leaves make this an exotic standout. It is drought-hardy and adaptable to most soils.


These 500 plus Australian trees and shrubs have many admirers (and detractors in regions where they run wild). Their often picturesque forms and graceful, aromatic foliage combine with exotic colors in leaf and bark to produce a distinctive appeal. While most species are too tender for the Northwest, several have proven themselves here. All are very fast growing (3-10 ft. a year), drought-hardy and good in most soils, but they really need full sun.

Eucalyptus archeri / ALPINE CIDER GUM

A slender tree to 40 ft. or more before developing a wider, rounded top. Small, egg-shaped to triangular leaves of deep blue gray line green twigs; bark is flaking brown over patches of red and green. Not the most exciting species, but nice when against a dark backdrop, and very hardy.

Eucalyptus gunnii / CIDER GUM

Simiilar to E. archeri, with which it is easily confused. Cider gum tends to have pale, tan bark, white twigs and silvery leaves. It is renowned for hardiness, but is variable on that point. Most have survived recent decades here just fine. Some trees have reached 80 ft. or more.

Eucalyptus pauciflora ssp niphophila / SNOW GUM

This is likely the hardiest species. Imagine a madrone, with its curvaceous lines, but with white, cream and gray trunk and narrow, blue leaves. Snow gums reach 30 ft. fairly quickly, then more slowly develop a broad, rounded crown to 50 ft. or more. They make choice landscape features.

Eucalyptus perriniana / SPINNING GUM

Grown also for its silver-dollar juvenile foliage, spinning gum becomes a small tree 30-50 ft. high with a broad, irregular crown of willowy, blue-green leaves on red or silver twigs. The tan bark of the trunk peels in sheets; branches are smooth, satiny olive-gray. The low, sprawling habit requires plenty of room, but the tree is very hardy.

Eucryphia x intermedia 'Rostrevor'

This is the hardiest of the several evergreen species in this glorious genus of Southern Hemisphere trees. Sparkling, fine-textured foliage in soft billows cover its narrowly pyramidal form from head to toe. Fragrant white flowers resembling Hypericum open in summer. Growth is fairly fast and contented plants will reach 30 ft. tall. Such a first rate ornamental deserves wider use, though it is risky in the colder zones. It is best with partial shade and occasional watering.

Ilex purpurea (I. chinensis) / ORIENTAL HOLLY

Holly is a bad word here in the Northwest, where English holly (I. aquifolium) is such a weed. This completely innocent species, however, is still rare and deserves wide use. No Christmas holly, it is a slender tree to 60 ft. tall with narrowly oval, bright green, completely spineless leaves 3-5 in. long. The soft, lustrous foliage is very cheering in gray winter light. Oriental holly seems drought-hardy and adaptable, happy for decades in the few spots locally where it has been planted.

Laurus nobilis / BAY

This Mediterranean native is the bay of cooking. Its narrowly oval, dark green leaves are sweetly aromatic. They cover a broadly pyramidal form to 30-40 ft. tall. Some trees are very slow and haven't reached even 10 ft. in decades; others are that tall or more in five years. Bay wants good drainage, but grows well in sun or shade. It needs shelter in colder zones.

Ligustrum lucidum / GLOSSY PRIVET

A dense, rounded tree to 30 ft. or more, glossy privet presents a tailored and tony appearance. Crisp, glossy oval leaves are overtopped in early summer by lilac-like clusters of creamy white flowers. While very showy, these have the typical privet smell, which some people dislike. Tiny black fruits follow, which can lead to crops of unwanted seedlings. Snows have taken a toll on some privet trees in the past, but others have been unharmed. The tree takes drought but not temperatures below 10F.

Lithocarpus densiflorus / TAN OAK

Native in southwest Oregon and the mountains of California, this handsome tree is part oak and part chestnut. Its cream flower spikes, unpleasantly odor and all, resemble those of chestnut; the acorns in their bristly cups connect it to the oaks. Thick, 3-5 in. leaves , toothed and deeply veined, make up a narrow crown of horizontal to drooping branches reaching 100 ft. or more. This is a very worthy native, yet not much planted. It has unfortunately been the prime victim of sudden oak death, a bacterial disease that has wiped out many acres of forest in California, so many are reluctant to plant it. From the Willamette Valley north, which is well away from the infected areas, it shouldn't be a concern.

Continued next time

Monday, June 15, 2009

What To Grow- Perennials

This is just a selection of our many native species, favoring those that are easiest to grow in average conditions and excluding the hard-to control.

Aquilegia formosa / WESTERN COLUMBINE

Delicate and distinctive perennial for shade. Divided, blue-green leaves and graceful red and yellow flowers nodding atop wiry, branching 3-4 ft. stems. Drought-hardy, but blooms longer where moist.

Aruncus dioicus / GOAT'S BEARD

A tall, bushy perennial with several stems arching out from the ground, 4-6 ft. tall in bloom. Airy leaves are divided into may toothed leaflets. Tiny white flowers arranged in large, nodding plumes make a graceful show in early summer. A real beauty that needs a moist, partly shady spot.

Aster chilensis / COAST ASTER

Bouquets of summer flowers in shades of lilac blue on a bushy 2-3 ft. tall plant. Grows wild on coastal meadows; easy and drought hardy in gardens.

Camassia/ CAMAS LILY

Starry flowers in shades of blue are arranged along sturdy stems above a clump of narrow leaves. The great camas (C. leichtlinii) grows 3-4 ft. tall with light blue flowers; common camas (C. quamash), is half as tall, with deep blue flowers. Both are variable, sometimes white. Easy to grow, they like moist soil in spring, dry in summer.

Carex tumulicola / FOOTHILL SEDGE

Of our many sedges, this one is among the most drought-hardy and adaptable. Thin, bright green leaves form a dense 15 in. mound, with wiry flower spikes above that. Evergreen and always attractive, it makes a great meadow or even a formal edging, in sun or light shade.


Deciduous perennial carpeting patches of forest with delicate, dissected, pale green leaves up to 12 in. high. Soft pink, rose or white flowers nod from 12 in. stems in spring, and often into summer where moist. Charming and indispensible for shade; more vigorous than it's delicate looks would suggest.

Erigeron glaucus / SEASIDE DAISY

Evergreen mats of broad, blue-green leaves make this a decent groundcover. Add to that a nearly year-round crop of fat, lilac daisies on short stems and you have a fine landscape plant. Give it sun and sandy soil.

Erigeron speciosus / CASCADES FLEABANE

Aster-like flowers in shades of lilac blue to rosy pink cover rounded, leafy mounds 2 ft. tall in summer. This native is so garden-worthy it is the parent of several cultivars. Good in sun or part shade.

Eriophyllum lanatum / OREGON SUNSHINE

Too rare in gardens, yet easy to grow in sun and sandy soil. Deep mats of divided, wooly gray and white foliage spread 2 ft. wide. Bright golden yellow daisies on short stems make a brilliant glow for many weeks in spring.

Fragaria chiloensis / COAST STRAWBERRY

Long popular as groundcover, this evergreen needs well drained, preferably sandy, soil to thrive. Its glossy foliage is sprinkled with white flowers in spring, but alas, it seldom fruits in cultivation. It does well in sun or moderate shade.

Fragaria virginiana / BLUELEAF STRAWBERRY

Little known except to hikers, this strawberry is another nice groundcover, notable for its blue-gray foliage. Typically evergreen west of the Cascades, it spreads as strawberries do to form large mats. Tiny but luscious berries are a bonus. Wants sun, good drainage.

Heuchera micrantha / SMALL-FLOWERED ALUMROOT

Mats of rounded, lobed, shiny leaves make good evergreen cover in shade or part shade. Tiny cream flowers in misty sprays in early summer. Attractive and adaptable, but needs good drainage.

Iris douglasiana / DOUGLAS IRIS

These evergreen perennials are among our most useful landscape plants. Glossy, arching strap-shaped leaves make broad clumps 12-18 in. high. Typical iris flowers in patterns of white, lilac, blue, purple and cream just clear the foliage in April or May. Hybrids with this iris and other Pacific Coast species- the Pacific Coast Hybrids- extend the color range into yellow, rust-red, mahogany, burgundy, amethyst, peach, etc.

Penstemon serrulatus / COAST PENSTEMON

This is one of the few among our dozens of penstemons that is really easy to grow. Makes a bushy clump of leafy stems topped by spikes of rosy pink to purple flowers in summer. Usually reaches 2-3 ft. tall. Adapts to damp or dry situations, in sun.

Polystichum munitum / SWORD FERN

So common, yet such a good plant. A large evergreen fern with many 2-4 ft. fronds. Great as a large scale groundcover, fine in small groups with other ferns, mahonia, rhododendrons, almost anything shade-loving. These will even grow in sunny rockeries!

Sedum spathulifolium / BROADLEAF STONECROP

Clinging to rocky outcrops along the coast and Puget Sound, this handsome succulent makes mats of chalky white rosettes, usually tinged pink or purple. Yellow flower clusters open in spring. Great cover in rocks or gravel in sun.

Tellima grandiflora / FRINGECUP

Evergreen clumps of rounded, scalloped leaves make a nice groundcover in shade. Tiny creamy cups along 2-3 ft. wands in spring slowly age to pink over many weeks. A lovely but overlooked native.

Tiarella trifoliata / FOAMFLOWER

This Heuchera relative spreads a small carpet of variously lobed or divided leaves over the forest floor, overtopped with a mist of tiny white flowers. Evergreen and surprisingly drought-hardy, foamflower is a charming addition to the shade garden.

Vancouveria planipetala / UPSIDE DOWN FLOWER

An evergreen groundcover from redwood country, making small patches of glossy leaves that are divided into triangular leaflets. Tiny white flowers suggesting parachutes dangle from wiry stems. A fine, small scale cover in shade and woody humus. Unfortunately scarce in nurseries.