Not Just Japanese Plants, Part I: Pacific Northwest Native Shrubs In Our Garden

Vaccinium ovatum (photo by Aleks Monk, 5/10/14)

By Corinne Kennedy

Juki Iida, designer of the Seattle Japanese Garden, decided that the Depression-era stone bridge at the south end of the pond should remain, and become a part of the Japanese-style garden he was creating.  He also chose to include Pacific NW native plants – even though they’re not found in the gardens of his native Japan.  Both decisions are consistent with the essential nature of Japanese gardens – that they be “rooted in place,” reflecting the landscape/culture where they’re created.  For me, the NW native conifers, shrubs, perennials, groundcovers and ferns planted in our garden blend seamlessly with the Japanese natives traditionally included in Japanese-style gardens.

In this month’s article, I’ll consider several of our garden’s Pacific NW native shrubs.  Most are plants in the heather family (Ericaceae) -- with small, delicate, urn-shaped spring flowers.  In fact, our region is characterized by the predominance of shrubs in this family.

Two species of huckleberries -- among the most important of our native Ericaceae -- appear in our garden.  Vaccinium ovatum (Evergreen Huckleberry) is planted in several areas at the south end of the pond and along the southwest fence (Areas F, H, W, ZZE & ZZW) – most prominently as part of the living fence surrounding the Tea Garden (roji).  It’s a medium-sized shrub with small leathery foliage, pinkish urn-shaped flowers and small, blue-black, sweet/tart fruit.  Commonly seen by hikers in the Cascade and Olympic Mountains, it grows at low elevations in coniferous forests and forest edges, and provides habitat for hiding and nesting birds.  Traditionally, Native Americans ate the berries fresh, often with oil, or dried into cakes.

Red Huckleberry (Vaccinium parviflorum) is planted in the southwest area of the garden (Y, Z, ZZE & ZZW).  It’s a deciduous shrub common at low to middle elevations.  It appears in coniferous forests and forest edges -- and grows best in soils rich in decaying organic matter – including on logs and stumps.  Branches are strongly angled, and bright green when young.  The urn-shaped flowers are greenish-yellow or pinkish, and are followed by small, sour, bright red fruit.  Traditionally, berries were eaten fresh, dried or smoked.  Leaves and bark were used to make a gargle for sore throats.

Salal (Gaultheria shallon), also in the heather family, has white or pinkish urn-shaped flowers like those of huckleberries.  The spring flowers are followed by dark blue, berry-like fruit.  Foliage is leathery, egg-shaped and evergreen – and like the huckleberries, is arranged alternately on the stems.  Gardeners today are suspicious of its rapidly spreading, suckering habit.  Common in coniferous forests, on bluffs and near the coast, it frequently forms a continuous shrub layer – and sometimes impenetrable thickets.  Traditionally, fruit was eaten fresh, dipped in grease, or dried.  Most of our garden’s plants are in the southwest and Tea Garden areas (W, ZZE & ZZW).

The height of all three of these shrubs varies considerably, and may reach over twelve feet -- depending upon the amount of shade and moisture available. 

Mahonia nervosa, with Gaultheria shallon leaves at bottom of photo (photo from Washington Native Plant Society)

Cascade Oregon Grape (Mahonia nervosa) is one of my favorite native plants.*  Most of the plants in our garden are in Area ZZW, along the west fence at the south end of the garden.  It’s a tough, drought-tolerant, low-growing shrub with bold, lustrous, holly-like evergreen foliage and an upright/spreading habit almost like that of a Sword Fern.  The long, leathery arching leaves are composed of 9-19 leaflets.  Bright yellow flowers appear in upright clusters in May, followed by tart, waxy blue berries – covered by a whitish coating (known as a “bloom”).  It commonly reaches about 2 feet tall, but spreads slowly by underground stems.  In the wild, it appears in dry to moist conditions -- in open to closed forests at low to middle elevations.  Traditionally, the berries were mixed with other, sweeter fruit – and the bark & berries were used medicinally for liver, gall-bladder and eye problems. Surprisingly, the inner bark and roots are bright yellow in color, a characteristic of all plants in the barberry family.

It may surprise Seattleites that the rhododendrons in our garden aren’t Pacific NW native plants – and that rhododendrons aren’t planted in gardens in Japan.  However, rhododendrons do well & are planted throughout our area, so Mr. Iida allowed them to be used in the garden – despite their gaudy flowers.  Our native species, on the other hand, aren’t commonly planted in residential or public gardens, and are rarely available for purchase.  Of the two, Rhododendron macrophyllum (Pacific Rhododendron) is our state flower.  It has pink or rose-purple flowers in showy clusters, and appears in forests and forest edges, especially on the Olympic Peninsula.  It’s also a member of the heath family.  For these reasons, I believe it would be appropriate to add it our palette of NW native plants.  I’d love to see it planted in the Mountain and Woodland Areas of the Seattle Japanese Garden.

* The genus of Cascade Oregon Grape, a shrub in the Barberry Family (Berberidaceae), has recently been changed back from Mahonia to Berberis.  However, I've used Mahonia nervosa in this article because it remains in common use.

Corinne Kennedy is a Garden Guide, frequent contributor to the Seattle Japanese Garden blog, and retired garden designer.