Superb and sophisticated: Perennials for shade

To some gardeners, the idea of growing things in shade can be rather daunting.
-- Jane Taylor

Tricyrtis hirta 'Togen'
I was recently invited to direct a workshop for novice gardeners in the Toronto area. A diverse group of urban professionals gathered on a glorious Saturday morning, united by a single goal -- how to create their own beautiful shade garden. Many of these individuals comfortably exercised their artistic talents for interior design, but felt helpless when approaching their own back gardens. It's not surprising. The numerous selections available at the local garden centre can be daunting to the novice gardener.

Several participants had purchased older homes with established gardens, while others were starting from scratch. The result of their efforts to date had been discouraging. The plants had not performed as expected.

When asked about their particular site, few could describe their own garden conditions. How many hours of sun did the garden enjoy? If mostly shade, was the shade created by tall buildings (permanently shady) or by neighbouring trees (allowing sunlight to filter through, especially in the spring)?

Was the soil sandy and well drained or humus-rich and moist? Do large trees absorb all available moisture? Or, was the garden located in a low spot where water collects and is slow to drain? These are just a few of the simple questions your customers should be able to answer before deciding which plants to purchase for their garden. Most gardeners are more apt to select anything in bloom from the displays, disregarding the ideal growing conditions required for success.

The key to success lies in selecting a great plant for the ideal location. The most common error is placing a sun-loving plant in shade (to wallow) or a shade-loving plant in full sun (to fry). Once you have spent time getting to know your specific garden conditions, you can confidently select plants that will thrive and prove to be a beautiful and wise investment in your garden.

Charming spring gardens
While visiting Toronto, I had the great pleasure of studying some of the older, established neighborhoods. Many of these homes are nestled beneath a canopy of mature trees. Majestic oak trees tower above the stately homes. A successive pruning of all lower branches was executed over the years, in an attempt to allow as much sunshine as possible to reach the gardens below. And what glorious gardens they are!

One of the secrets of enjoying a successful shade garden is to take advantage of the early spring season. There is no need to wait for summer to add colour to a shade garden; many early blooming spring bulbs and woodland perennials will provide a colourful show before the canopy of leaves returns.

Carex siderostica 'Variegata'

Geranium macorrhizum

Tiarella cordifolia 'Oakleaf'

Hosta 'Stiletto'
Many of the older gardens were carpeted with Scilla, commonly known as bluebells. The gardener at one such home, had obviously given up the battle to maintain a lawn. The front garden was gently terraced using natural stone. A generous fieldstone walk welcomed visitors to enjoy the informal plantings of spring flowers, as they made their way to the formal main entrance. Several varieties of daffodils joyously heralded the glorious spring day, above a sea of gentian-blue flowers.

In such a wooded neighbourhood, squirrels can present quite a challenge to gardeners, tulips being a preferred gourmet feast. However, daffodils are poisonous to squirrels and consequently are left alone. They should be planted in well-drained soil. According to Patrick Lima, "Daffodils are encouragingly easy to grow. True low-maintenance plants, they are cold-tolerant, insect-proof, healthy and enduring." Who could ask for more?

Closer to the home itself, spring blooming shrubs such as forsythia, viburnum, rhododendron and lilac were preparing for their later spring performances.

Elegant black cast-iron urns, situated on either side of the front steps added a formal touch. They featured seasonal displays of pussy-willow branches, crocus, grape hyacinth and early daffodils. Cars and pedestrians alike were slowing down to enjoy the garden's magical display of colour.

It was a romantic garden for spring, but what happens when the bluebells and daffodils are finished blooming? The trick is to plant the bulbs among later sprouting herbaceous perennials. The emerging perennials will disguise the fading foliage of the bulbs. For longevity and health of the bulbs, it is essential that the foliage be allowed to die back naturally. This stage is necessary to feed the bulb for next year's blooms. In this particular garden, a blanket of Cotoneaster would cover the fading bluebells.

Daylilies, perennial grasses and Siberian iris make great companions for daffodils, with their similar, strap-like foliage. Situate the perennials together in groups of three to five of the same plant. Place the daffodils eight to 10 inches from the crowns of the companion perennials, weaving them through the planting to create an informal grouping. None of the bulbs should be planted toward the front of the perennials, rather between and behind them so that the emerging foliage will completely hide that of the bulbs.

Another successful marriage for shade gardens, combines Muscari, (grape hyacinth) and Alchemilla mollis, (lady's mantle). The grape hyacinth will bloom from April to early May. As the flowers fade, the delicate foliage of the lady's mantle emerges to form a blanket of delicately serrated, velvety leaves. These discreetly mask the fading grape hyacinth leaves. In early fall, the grape hyacinth offer fresh grassy foliage, which can appear untidy in the front of a border. The lady's mantle, having been cut back after blooming, will provide a luscious foliage cover once again.

Recommended perennials for shade
These shade tolerant plants enjoy a woodland-type setting of humus-rich and moist conditions. They offer interesting additions to the typical hosta, astilbe and ferns found in most shade gardens:

Tricyrtis (Japanese toad-lily)
Fall blooming shade perennials are always welcome -- these are both easy and unique. Arching stems produce a fall display of bizarre white star flowers, heavily spotted with dark purple. This plant deserves a special spot where it can be seen up close.
Height: 2-3', Spread: 1-2', needs a rich, moist soil. Blooms Sept-Oct.

Tiarella cordifolia 'Oakleaf' (Foamflower)
This is an exceptional plant with deeply lobed foliage, similar to that of an oak leaf. It offers deep red winter leaf colour and pale pink spikes of flowers in early spring. Similar in habit to coral bells, it makes a great edging for the woodland garden.
Average height: 6"-12", Spread: 12".

Carex siderostica 'Variegata' (Sedge)
Narrow bright green leaves are boldly edged in creamy white. It can be mistaken for a narrow-leafed hosta. It spreads underground to form a loose patch, making it a good ground cover or edging choice. Fresh spring growth is tinged with pink, echoing many spring blooming shrubs and bulbs in the shade garden. Blooms are insignificant.
Height: 8"-12", Spread: 12" -24".
(Once placed, this frequently becomes the favourite of many clients).

Hosta 'Stiletto'
This unusual dwarf hosta is truly outstanding. It has narrow, grass-like foliage, leaves are green with rippled white edges. Luxurious lavender/purple flowers appear in the late summer. It is a vigorous grower. Used as an edging, it permits gardeners an opportunity to include the increasingly popular grass forms in their shade gardens. A dry-shade location offers the gardener a demanding, though not impossible challenge. The following workhorse plants will grow in the most difficult situation-in the dry shade of a large tree.
Height: 6", Spread 12"

Saxifragas x urbium 'Aureopunctata' (Golden London pride)
Gardeners eager to impress visitors with difficult Latin names will win points for this selection! This plant forms a vigorous, low, evergreen mat -- the leaves are heavily spotted with gold. This is an excellent groundcover for dense, shady areas -- even under trees.
Height: 8-12", blooms May-June.

Geranium macrorrhizum (Bigroot cranesbill)
The velvety-soft foliage is extremely fragrant, reminiscent of lemon. They are heat- and drought-tolerant, forming a non-invasive groundcover. The foliage perks up very early in spring and takes on a lovely red and orange tone in the fall. Flower colour varies from light pink (Ingwersen's Variety) to magenta (Bevan's Variety), with blooms appearing very early in the season.
Height:12" Spread 24".

Luzula sylvatica (Greater wood rush)
These grass-like plants are native to moist woodland site, but tolerate dry shade. They spread to form a low, dense groundcover of flat, softly hairy leaves. Evergreen (trim in early spring). The variety 'Marginata' with each leaf edge trimmed in cream is worth seeking to brighten dark shady areas.
Height/spread:12". Not invasive.

(My sincere thanks to John Valleau of Valleybrook Gardens for supplying the photography.)