Beautiful ways to use shade plants in mountain or woodland settings
Like their counterparts in the sun, gardens made for the shade can take on formal or informal personalities. In Boulder, Colorado, for example, landscape designer Robert Howard created a shade border with the formal look of an English garden. In Bellevue, Washington, Nita and Johnny Therrell planted a woodland garden that retains the informal look of the wild forest from which it sprang. Shade plants need little extra fertilizer if they’re grown in good soil (nitrogen only makes them leggy), but competition for water can be intense when ground covers are planted over tree roots. Water whenever soil dries out.
Howard created this shady oasis beneath a pair of apple and pear trees. First he built a retaining wall of dry-stacked stone wall, then dug compost into the top foot of soil, avoiding the tree roots. He set the plants close together to keep weeds down.
Here, a mile above sea level, the light is so intense that it spurs strong growth, even in shade. This light made it possible to combine true shade-loving plants–including dead nettle, hosta, and meadow rue–with perennials that tolerate bright shade at higher elevations, such as catmint, ‘Berggarten’ sage, and veronica.
Next: A Washington Woodland
The Therrells filled their entry garden with azaleas, rhododendrons, Japanese maples, and other shade-tolerant exotics, but left most of the rest of their property as woodland.
The ground is carpeted with moss and a generous array of ferns. Spring-blooming woodland flowers, including bleeding hearts, trilliums, and violas, dot the forest floor from March through May; red-flowering currants and bunchberries pop out in April; and native azaleas and rhododendrons light up the woods in May. Ocean spray and twinflowers close out the season in June. After that, the exotics, including hostas and impatiens, carry on the floral show.
Shade plants in general and native plants in particular tend to have an open, informal look–a characteristic that leads many gardeners to think of them as plants suitable only for the wild garden. But Nita Therrell calls them rambunctious plants that simply want a little training. Therrell shears her huckleberry, ocean spray, Oregon boxwood, and salal plants close, and and she even maintains a perfectly sheared rhododendron hedge in the entry garden.
SHADES OF DIFFERENCE
Ironically, although shade plants usually cannot tolerate full sun during the hottest part of the day, most grow and flower best when they get plenty of light. They love the light shade cast by high-arching tree canopies, as well as the shade common in gardens that are shaded to the south but open to sky on the north. Generally, they don’t perform as well in full shade.
Experiment to see what works for your garden: If your plants grow too leggy and fail to flower, they’re probably getting too much shade. Transplant them in a brighter spot (or thin out any overhead branches that are casting shadows).
Because so many shade plants come from woodlands, they thrive in the kind of porous, humusy soil typically found in the forest. If you have this kind of soil, maintain it by mulching with compost or leaf mold twice a year. If you don’t, create your own by tilling a 3- to 4-inch layer of composted organic matter into your soil. Or combine 2 parts organic amendment (compost or peat moss) with 1 part sand and 1 part garden loam to form a layer of soil at least 8 inches deep to spread over the ground.
Next: Ground covers & perennials
GROUND COVERS & PERENNIALS
• Bunchberry (Cornus canadensis). Deciduous. White flowers appear in May, then red berries; 6-inch plant. Sunset climate zones 1-7.
• Dead nettle (Lamium maculatum). Deciduous in hard winters. Silvery white leaves have green edges; usually pink or white flowers; 6 inches tall. All zones.
• Hosta. Deciduous. Solid or variegated, blue to green leaves; sometimes-fragrant flowers. Zones 1-10, 12-21.
• Japanese spurge (Pachysandra terminalis). Evergreen. Attractive, 6-inch leathery leaves. Zones 1-10, 14-21.
• Meadow rue (Thalictrum species). Deciduous. Airy foliage grows 3 to 6 feet tall. All zones.
• Redwood sorrel (Oxalis oregana). Deciduous. In spring, pink or white flowers rise over a cloverlike carpet. Resists slugs. Zones 4-9, 14-24.
• Sweet woodruff (Galium odoratum). Deciduous. Delicate ground cover with white, mellow-smelling May flowers. Resists slugs. Zones 1-6, 15-17.
• Vanilla leaf (Achlys triphylla). Deciduous. Butterfly-like leaves emerge in April; flowers are cream-colored; to 1 foot tall. Zones 2-7.
• Wild ginger (Asarum caudatum). Evergreen; native to the woods of the Coast Range. Big, heart-shaped leaves have gingery scent when crushed; handsome, dark green carpet to 10 inches. Zones 4-6, 14-24.
FERNS & SHRUBS
• Coast rhododendron (R. macrophyllum). Evergreen. Pink flowers in May or June. Tends to be leggy unless you prune hard after bloom; 10 to 20 feet tall. Zones 4-6, 15-17.
• Maidenhair fern (Adiantum aleuticum). Deciduous in hard winters. Airy-looking, delicate fronds; 1 to 2 feet tall. Zones 1-9, 14-24.
• Ocean spray (Holodiscus discolor). Deciduous. Western native with toothed leaves bears clusters of creamy white summer flowers; 3 to 20 feet (taller in very rich, moist soil). Zones 1-7, 14-17.
• Oregon boxwood (Paxistima myrsinites). Evergreen. Looks like a dark, dense boxwood; 2 to 4 feet tall. Zones 1-10, 14-21.
• Oregon grape (Mahonia aquifolium). Evergreen. Holly-shaped leaves; yellow spring flowers followed by sour, grapelike fruit; to 8 feet. Zones 1-21. Longleaf mahonia (M. nervosa) grows to 2 feet; zones 2-9, 14-17.
• Red huckleberry (Vaccinium parvifolium). Deciduous. Airy branches with light green leaves are dotted with edible red berries in summer; 4 to 12 feet tall. Zones 2-7, 14-17.
• Salal (Gaultheria shallon). Evergreen. Dense, unthirsty shrubs produce edible (if bland) purple summer fruit; 2 to 10 feet. Resists slugs. Zones 3-7, 14-17, 21-24.
• Sword fern (Polystichum munitum). Evergreen. Takes some drought. Shiny, dark green fronds; 2 to 4 feet tall. Zones 4-9, 14-24.
• Western azalea (Rhododendron occidentale). Deciduous. Fragrant white or pink flowers with yellow throats; to 8 feet tall. Zones 4-9, 14-17, 19-24.