A frequent question to the Gardening Advice Line written by the Vancouver Island Master Gardeners Association volunteers.
Question: What can I plant against a north facing wall? I live in Zone 6-8 on Vancouver Island.
Here are some suggestions:
Impatiens (Impatiens walleriana):
The ubiquitous impatiens is one of the most popular bedding plants for any shady locations, thanks to its profusion of color and long bloom season. For some years, impatiens had virtually vanished from garden centers because of a wide spread fungal disease, downy mildew, that virtually wiped out seed stocks. Recently, however, several disease-resistant strains have been developed, and impatiens are once more a viable choice as a bedding plant for shady gardens. Impatiens do well in nearly complete shade, but they will also tolerate relatively sunny conditions if they are kept well watered.
Wax Begonia (Begonia Semperflorens Cultorum Group):
The group of plants within the Begonous known as wax begonias are fibrous-rooted plants that form mounds of fleshy, waxy leaves ranging from dark green to bronze in color, with loose clusters of small flowers that bloom throughout the season. Small varieties grow to about 6 to 8 inches; taller varieties are 10 to 12 inches. Wax begonias are normally used as a bedding plant, planted in masses or as an edging. Wax begonia is a versatile plant that can work in full sun as well as part shade. Space the plants well apart to improve air circulation and prevent fungal problems.
Tuberous Begonia (Begonia Tuberosa Group):
Related to the wax begonias but much different in appearance are the tuberous begonias. Unlike the wax begonias, these don't tolerate much sun, but the huge leaves and large neon-bright flowers will brighten shady spots like no other flowering perennial. Often grown in pots, tuberous begonias also make a good bedding plant in the right locations—dappled shade or reflected light. Tuberous begonias grow 12 to 18 inches high with a similar spread. They bloom from July through September with brightly colored flowers that seem to glow in the shade. Tubers should be planted after the danger of frost has passed. Regular fertilization will keep these plants blooming profusely.
Common Bleeding Heart (Lamprocapnos spectabilis):
Common bleeding heart is an excellent perennial choice for spaces along north-facing walls. This is a medium-sized, 2- to 3-foot plant that produces clusters of pink and white flowers along arching stems in spring. In sunnier locations, supply the plant with more water to compensate. Bleeding hearts are early-season plants that put on their show before the summer's heat arrives, and in warmer climates, the plant's foliage usually fades away as the summer approaches. In cooler climates, bleeding heart tolerates more sunshine. Bleeding hearts are best planted among other plants that can fill in when the foliage fades in summer heat.
Periwinkle or Creeping Myrtle (Vinca minor):
If you need something shorter than a perennial like common bleeding heart, look into ground covers for areas along north-facing walls. A popular type for shade is periwinkle, also known as creeping myrtle. Periwinkle forms a viny mat 3 to 6 inches tall, flowering in May and June. It makes an excellent ground cover around bleeding heart and other perennials, or beneath shrubs and small specimen trees. Regular fertilizing will brighten the color of the green leaves and cause the plant to spread. In some regions, periwinkle is regarded as invasive, so check with local experts before planting it.
Lilyturf (Liriope spicata):
The garden spaces along north-facing walls are often dry as well as shady. These areas can be notoriously dry because the eaves intercept rainfall. The ideal plants for these areas are those known to do well in dry shade. Lilyturf is one such plant, a grasslike perennial that grows 9 to 18 inches high. Small flowers appear among the leaves in August through September, though lilyturf is prized more for its grasslike foliage. Lilyturf tolerates shady conditions, though it performs better if given more sunlight. It should be mowed down in early spring to stimulate new growth.
Hosta (Hosta spp.):
The quintessential foliage plant for shady areas is hosta. Also known as the plantain lily. Many types of hosta are good low-growing plants for your north side. Although not known for flowers, the sheer diversity of green hues found in the leaves of various cultivars make hosta more than just a ground cover plant. Increased sunlight can change the leaf colors of some types of hosta, and those with yellow leaves typically are more tolerant of sun.1Hostas are extremely easy to grow and care for, though they can be susceptible to damage from slugs and snails, especially if the ground is heavily mulched. You can easily propagate new plants by dividing the root clumps.
Bugleweed (Ajuga reptans):
Another ground cover tolerant of a number of conditions is bugleweed. This perennial will bloom better in sunny conditions, but it makes an excellent shady ground cover, growing 6 to 9 inches and spreading rapidly into a thick mat. Blue flowers appear in May and June where conditions are right, but this plant is more notable for its shiny dark green or bronze leaves. The plants can be cut back to the ground after flowering to stimulate new growth.
Climbing Hydrangea (Hydrangea anomala ssp. petiolaris):
If you wish to grow climbing plants against a north-facing wall, you have a narrower variety of choices, but climbing hydrangea is one woody climbing vine that blooms nicely, is well-behaved, and does well in shady areas. This plant can grow as much as 50 feet long and will spread out into a ground cover if it is not trained up sturdy trellis or structure. White flowers appear in May to July. Climbing hydrangea can become a heavy, unruly plant, so make sure to provide it with a sturdy structure if you expect it to climb.
Yew (Taxus spp.):
When it comes to choosing plants for the areas along north-facing walls, you have a greater number of options when it comes to shrubs, especially if you are content to enjoy nice foliage without flowers. Yew bushes (Taxus spp.) are needle-bearing evergreens and a classic choice for shade. The types used for landscape purposes are often Taxus x media hybrids, and they can range from 2 feet to 20 feet in height, depending on variety. These shrubs do not offer a floral display, but they can give you pretty berries (arils, technically). These shrubs have good tolerance for urban conditions, but make sure soil is well-drained, as they will perish if they languish in wet soil.
Flowering Quince (Chaenomeles speciosa):
Well-rounded gardens generally include at least one flowering shrub or small tree, and there's no reason you can't also include one in garden spaces found along north-facing walls. Flowering quince is incredibly easy to grow, tolerating almost any soil. Growing 6 to 10 feet high, flowering quince is a dense rounded shrub with spiny stems. It blooms in March to April with white to scarlet flowers that appear before the leaves open. The leaves are reddish-bronze when the open, maturing into deep green. Small fruits ripen to red in the fall and are attractive to birds. These shrubs bloom on old wood, so any pruning should be done immediately after flowering is complete, so that new wood has a chance to mature for the following spring.
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