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Using Wall Shrubs to Your Advantage

Our new home came with treasures: a sunny flagstone patio and a view of the mountains. It also came with a humungous, bare outside wall. Worse still, neither the siding, nor my husband, could accept anything that would attach to this monolith—no Boston ivy or rambling rose would scale these heights. I needed wall shrubs. Fast!

wall

Wall shrubs are like perfect screens. They’re appreciated both for what they can do—camouflage an eyesore, add flowers to a vertical space, create appeal without the uniformity of a hedge—and for what they don’t need: trellising or attaching to a wall’s surface. 

Wall shrubs can be four or fifteen feet tall, evergreen or deciduous. Some wall shrubs become such because they thrive best with the cozy protection of the wall. Other plants become wall shrubs because they’re amenable to the idea; they have a strong branching structure and an affinity to a hard pruning that shapes them shallow and wide.

Shrubs for Sunny Walls
Creeping blueblossom (Ceanothus thyrsiflorus var. repens; USDA Zones 7–9) barely reaches two feet tall when grown as a groundcover, but if it’s placed against a wall and allowed to grow upward it can easily reach seven to eight feet tall. An evergreen, it blooms for a long time in early summer, with stellar blue flowers.

Creeping blueblossom is typically seen as a ground cover, but it can be easily pruned to grow upward and shrubby when sited at the base of a wall.

Creeping blueblossom is typically seen as a ground cover, but it can be easily pruned to grow upward and shrubby when sited at the base of a wall.

‘Anne Russell’ Burkwood viburnum (Viburnum xburkwoodii ‘Anne Russell’; Zones 4–8) is often evergreen in milder winters. It has exquisitely fragrant whitish-pink flowers in late spring. To cheer the birds and lengthen the season of interest, it offers an encore of blue-hued berries.

Black lily magnolia is a small tree that can be trimmed to remain close to a wall.

Black lily magnolia is a small tree that can be trimmed to remain close to a wall.

The deciduous black lily magnolia (Magnolia liliiflora ‘Nigra’; Zones 5–9) reaches about 10 feet. It is beloved for its deep pink flowers in mid-spring.

Wall Shrubs for Part Sun

For a wall that’s shaded part of the day, the best shrubs are camellias. Evergreen, long-flowering and sturdy, these transform a blank wall into a showstopper. In warmer climates, try the autumn camellia (C. sasanqua ‘Setsugekka’; Zones 7–9). It flowers all winter, and it effortlessly acts as a trellis for midsummer-flowering (and semi-shade tolerant) Clematis ‘Silver Moon’. 

Autumn camellia

Autumn camellia

In colder climates, look for the sweet-smelling tea-oil camellia (C. oleifera), hardy to Zone 6 with a wall’s protection. 

Do remember that camellias can get grumpy with adjacent cement leaching into the soil. This is best counteracted with peat or mushroom manure. They detest dry soil, so keep them watered. Prune them just after they flower.

If you have just a half a day of sunlight, weeping forsythia (Forsythia suspensa var. sieboldii; Zones 5-8) will work. It has bright yellow flowers in early spring, echoing the early daffodils, and it’s easy to prune to fit any space. 

The tiny-leaved firethorn (Pyracantha x‘Mohave’; Zones 5–9) can also enhance a wall, bringing lacy white flowers in late spring and reddish-orange berries that start in late summer and last well into the winter. ‘Mohave’ looks terrific against brick or concrete. Disease-resistant., it can grow to 15 feet tall and wide but it is amenable to restrictive pruning (best done in late winter).

Shrubs for North-facing Walls
My favorite on difficult north-facing walls is ‘Moerloosei’ flowering quince (Chaenomeles speciosa ‘Moerloosei’; Zones 4–9), with its early spring blossoms of deep pink–tinged white and its fragrant fruit in the fall. Rising to eight feet tall and wide, flowering quince needs a firm hand with pruning or it can become a thorny mess. This is tricky; pruning in late spring is easiest, but you then lose some of the fruit. I find a middle ground by pruning it lightly each fall.

'Moerloosei' flowering quince

'Moerloosei' flowering quince

Sweet olive (Osmanthus delavayi; Zones 6–9) is what covers my own monolith. It has small evergreen leaves and an abundance of fragrant white flowers. There is a smaller variegated form, Goshiki false holly (O. heterophyllus ‘Goshiki’; Zones 6–9), reaching only to four feet, that many enjoy.

Finally, ‘Golden Guinea’ kerria (Kerria japonica ‘Golden Guinea’; Zones 4–9) brightens even the darkest of spots with its golden flowers. It reaches eight feet tall and wide. It can be pruned lightly or cut back hard every year or two.

Caring for Wall Shrubs:

  • Think of the pruning of wall shrubs as “shaping intentionally” as much as “cutting back.” The correct time to prune will be the same no matter where a shrub resides, so follow the typical recommendation for the species. When choosing growth to remove, work toward two goals: to keep the shrub fanned out against the wall, and to keep outward sprouting shoots cut back so they don’t poke you when you pass by.
  • Many shrubs like a bit of food each year, so I give my wall shrubs a few shovelfuls of well-rotted steer manure each fall and a sprinkle of an all-purpose fertilizer in early spring.
  • Keep a look out for the need to water. Eaves can block rain from reaching wall shrubs. They might not need water in winter, but there’s a good chance they will in the other three seasons.

Image credits (top to bottom):

Wall by Jisun Han

Blueblossom by John Rusk/CC BY 2.0

Magnolia by Wendy Cutler/CC BY-SA 2.0

Autumn camellia by Oregon State University/CC BY-SA 2.0

Flowering quince by peganum/CC BY-SA 2.0