Unique and we think very pretty evergreen Viburnum. Small perfectly round leaves are placed in threes around the stems. In summer the terminal branches host clouds, or cymes I should say of tiny white flowers. They have no fragrance but are pretty to look at.. Moderately growing rounded shrub of great symmetry to 4′ x 6′ in 7 years. Full sun to part shade in rich, well drained soil with light but consistent summer moisture. Takes very dry conditions when established. At first glance this does not look like a Viburnum- which is charming. Its a very pretty dense growing first rate evergreen.
Biome: Low Water/No Water
Rainfall in the Pacific Northwest takes an annual break during our summers when days are longest and hottest and evaporation far exceeds anything that falls from the sky. It makes sense to seek out plants that are adapted to dry summer conditions. A large selection of these plants are from the Mediterranean or are natives of the West Coast. Most importantly, these plants save water and money without sacrificing good looks. And many drought adapted plants actually shun summer water. Its wise to group these plants together and designate a no water zone. You’ll be amazed at what a beautiful vibrant garden you can have without irrigation. Find the right plants and then trust their built in adaptation- its a simple and smart way to garden. And it saves resources- as well as the gardeners precious time. The following plants once established will weather a hotter than normal summer without undue stress. That is one or more years after installation. The better you treat a plant in the beginning the sooner it will develop drought adaptation. The better established the more drought tolerant.
Climate Adapted Plants for Gardeners in the PNW
Viburnum ellipticum
Oregon Viburnum or Western Way Faring tree is a moderate to large native deciduous shrub. It stretches a little bit into W. Washington where it is rare but its primary populations are in western Oregon and south into N. California. Its found in moist to dry woods often on the margin where its can get at least half a day sun. It also thrives only much larger and lankier in outline in the shade. It easily tolerates winter inundation but is found on well developed soils in upland situations as well. Its common associates in the wild are Oregon white oak/Quercus garryana, Oregon Ash/Fraxinus latifolius, Cornus stolonifera. Leaves are round, glossy and scalloped and are very handsome on a well proportioned fountain shaped shrub. Shorter in full sun, taller in shade. This plant needs just a modicum of light watering for its first year and once it is thoroughly established you can set it free. In late spring off white cymes of flowers have the fragrance to me of raw potatoes. We had a large specimen of this shrub in our back 40 where I grew up near Eugene. In certain years it can produce quite a fall show with orange/red tinted leaves and translucent blue fruits. Blooms on wood from the previous year. Prune if needed AFTER blooming has ended. June. To 5′ tall in the sun to much taller in shade. Protect young plants from deer. Oregon native plant.
Viburnum henryi
Rare but wonderful evergreen viburnum that has pretty elongated leaves held symmetrically on thick stems. The growth habit is branching in tiers. This displays the lovely foliage as well as the cones of white summer flowers at the branch tip. These turn into red and then black berries eagerly consumed by wildlife. To 9′ tall and 8′ wide in wide vase shape. Part shade in rich, well drained soil with regular summer irrigation. Takes very dry conditions when established. Extraordinarily cold hardy to below 0ºF with no ill effects. Moderately fast growing. SW China.
Viburnum japonicum ‘Variegatum’
Unusual and actually superior form of this species with large glossy evergreen leaves splashed with yellow. In spring flat corymbs of flowers appear and remind me of lace. Red berries follow but are consumed by birds. This form is not prone to mildew which can afflict the green leaved form. So, we love it for it’s bold leaves that look good year round and easy demeanor. To 8′ x 8′ in 10 years. Full sun to quite a bit of shade. Doesn’t burn in sun. Adaptable. Light summer water once established. Very old specimens get by with no summer water. Excellent year round appearance. Take out green reversions if they occur. Blooms on wood from the previous season- prune if needed after flowering. Specimen. Nice shrub.
Spring bouquet viburnum or Laurusitinus is a common shrub in our climate. This form lightens up what can be a very pedestrian plant. The edges of the evergreen leaves are margined in cream with an interior of soft green. This makes a shrub that glows year round and can be used to lighten up dark corners. In autumn clusters of pink buds form and hold until mid winter. Then as the days begin to lengthen it opens these clusters which are lightly fragrant and white. Strong growing shrub that requires very little water once established. To 8′ tall and 5′ wide in 6 years. Full sun to part shade to high overhead shade. Nice looking, tough shrub native to the Mediterranean very easy to grow and long lived. If a green sport appears simply prune it off to the base to retain the variegated form. Water to establish. Not deer resistant. Excellent backdrop to a mixed border or trimmed into a contained hedge. Nice fast growing screen. Blue berries sometimes follow the flowers. Buds and flowers put on a show for months. Blooms on wood from the previous season prune after flowering if needed. Naturally dense and rounded.
Viburnum x burkwoodii ‘Anne Russell’
Really there is nothing like the clove/carnation/sweet fragrance of this shrub in late winter to early spring. The large clusters of flowers begin as pink buds and open to white. Nice bicolor effect along the way. Blooms 3-4 weeks. Evergreen to semi-evergreen to deciduous in arctic places. Large growing shrub that can attain tree like proportions with great age. To 8′ x 4′ in 7 years. Full sun to quite a bit of shade in rich to average well drained sites. Light consistent summer water speeds growth and increases spring flowering. Otherwise relatively drought adapted, especially in shade. Tolerate the most obnoxious sticky clay soils- especially on slopes. Plant where you can pass by the flowers and take a big ol whiff. Very easy to grow. Prune AFTER flowering.
Viola corsica
One of the parents of modern violas this perennial is short lived but while its around its never out of bloom- year round. Slender indigo blue flowers are small but profuse on a compact plant to just 6″ tall and barely wider than that. Seeds itself around prolifically…how the seeds find their way so far from the parent plant is natures mystery. It will germinate anywhere – cracks, beneath rocks. Sun, Shade. Very hardy to way, way below 0ºF. Light summer water during the hottest weather. Part shade in nearly any texture soil. Mediterranean wild flower.
Viola odorata (Parma) ‘Alba Plena’
This cool cultivar of Parma violet can be difficult to stumble upon. We love the plush double white flowers that sends its sweet perfume on the breeze in late winter to mid-spring. Parma violets are basically the Sicilian version of the common sweet violet (Viola odorata). They are not nearly as cold hardy or pernicious as the species and they tend to have much larger more opulent and fragrant flowers. Also, their leaves are distinctively glossy as opposed to matte. This little sweetie forms spreading patches and the long stems are a bit weak for the large double white flowers- they tend to bend. Excellent for small bouquets that you can sniff and sniff. In the garden they need a sheltered position away from the freeze and thaw and harsh conditions in the open. Instead coset them under large shrubs and among ephemeral early perennials such as Anemones, and small bulbs like species Crocus. Part shade- they bloom best with a bit of sun. Regular summer water encourages them to spread. This form seldom sets seed- I don’t think I’ve ever seen seed in fact. Pity. Rare plant.
Viola odorata (Parma) ‘Duchess du Parme’
There’s nothing like the smell of sweet violets in late winter and early spring. But the regular species in our climate is nothing less than a thug. It seeds and grows where you really would rather not have it. Well, forget that. Enter this exquisite fully double flowering Parma Violet. The rich violet blue flowers appear on long stems from January to April. Parma violets are the Mediterranean form of V. odorata and they are less hardy to cold and not so rampant. This form we have never seen set seed- but there are always exceptions. Very glossy green foliage frames the flowers well. Excellent in containers in an unheated greenhouse, conservatory. In the garden choose a protected spot (under evergreen shrubs for example) and give this violet rich soil with regular summer moisture. Tolerates full sun but looks better with some shade. Flowers tend to lean horizontally, they are great for cutting and making little fragrant winter posies. Spreads by runners to form a nice patch in time. Tolerates summer drought when established.
Viola praemorsa ssp. praemorsa
Canary violet or upland Violet has many subspecies in the PNW and west in general. This is our own Willamette Valley form of this intriguing handsome perennial. Large spoon shaped leaves have an underside with conspicuous hairs. The top of the leaf is glossier. In April-May bright yellow flowers appear. The bottom petal has conspicuous black whiskers. In our region this violet is local in the most undisturbed sites but it shows very good persistence in competition with non-native introduced grasses. My experience is that it favors rocky and scree sites that remain somewhat cool- for instance the north side of a steep slope. To 6″ tall and forming expanding plants. Winter deciduous. Arrives early in spring and can go summer dormant with high heat. Excellent planted in fall or winter and left to its own devices. Average to enriched soil yields the best results. This is one of the showiest violets native to the Willamette Valley. Fairly long lived. Little deer resistance. Some associated plants are Olysinium douglasii, Sedum spathulifolium, Dodecatheon hendersonii. Oregon native plant.