Lathyrus odoratus 'Matucana'
When the keen gardener runs out of horizontal space, it’s natural to look around for other surfaces to adorn with plants.
Some, like fences, the walls of the house, garages and sheds, are already there, waiting to be decorated; others, like pergolas, tepees, arches and screens, can be bought ready-made or constructed with some simple carpentry. The fun part is choosing what to put onto them, and the choice is wide. But a little thought beforehand can save you from numerous headaches later. Wisteria It can be a glorious sight in bloom, but planting wisteria against a house guarantees problems down the road. Its rampant growth will soon have it prising up the roof, while down below, its thirsty roots are busy invading the perimeter drains or, worse, the sewer line. On a sturdy pergola, however, it can spread without threatening its host, and be easily within reach for some judicious pruning as well. There are two main species of wisteria: Chinese and Japanese. The most common is the Chinese form (Wisteria sinensis) whose tassels of flowers all open at once before the leaves unfold. Japanese types (Wisteria floribunda) produce leaves at the same time as the flowers, but flower trusses are longer, generally more fragrant, and open gradually from stem to tip. Both species come in white, as well as the popular purple, and mature vines will produce elegant, long pods with a coating of silvery fur in winter. Honeysuckle This is another vigorous twining vine best kept away from the house. Honeysuckle has the advantage of several evergreen varieties, although the deciduous forms have larger flowers. Fragrant yellow and cream blooms make Lonicera japonica ‘Halliana’ one of the most popular of the former, while the variegated foliage of ‘Aureoreticulata’ also has its admirers, despite its susceptibility to mildew. Planting in partial shade helps. The so-called Dutch honeysuckles, early-blooming L. periclymenum ‘Belgica’ and the later ‘Serotina,’ dominate the deciduous category. Both are dark pink with yellow throats, well scented, and bloom over a long season. Two more good choices are L. x heckrottii ‘Gold Flame,’ with showy crimson and gold flowers, and L. periclymenum ‘Graham Thomas,’ which has fragrant ribbons of cream and soft yellow. Fans of tropical hues might prefer L. x brownii ‘Dropmore Scarlet’ or the dazzling orange but scentless newcomer ‘Mandarin,’ introduced by UBC. Hydrangea Where repainting a wall or solid fence is not an issue, climbing hydrangea (Hydrangea anomala ssp. petiolaris) has all-season appeal. It adapts best to a slightly rough surface that allows its hair-like aerial roots a good grip. Vines take a little while to establish themselves, but will eventually cover a sizeable surface. They leaf out early and offer a fine show of the typical lacecap flowers in pristine white. An advantage of this plant is that it will happily grow in considerable shade. A close relative, Japanese hydrangea vine (Schizophragma hydrangeoides) has larger flowers. The variety ‘Moonlight’ has a beautiful milky sheen to its leaves. Climbing hydrangeas are almost trouble-free, although slugs are partial to young plants.
Clematis If space is not available for one of these big beauties, the vast clematis family has some small and delicate members. Spring-blooming Clematis alpina and C. macropetala are quite modest in their reach, but offer a lovely sparkle of dainty bell-shaped flowers, mostly in shades of blue, pink or white. Like all of their family, they like their feet in the shade and their heads in the sun, as well as something to grip with their thin leaf stems, either fine wire or string, or the branches of a complementary shrub such as a rose or a viburnum. (When planting, be sure to separate the clematis and host plant root balls by about one-half metre.) ‘Frances Rivis,’ with slender, dark-blue trumpets, and pale lilac-pink ‘Willy’ are readily available Alpina types, neither growing to much more than two metres. The Macropetala group is slightly more vigorous at around 3.5 metres. There is a wider choice here, including ‘Markham’s Pink,’ blue ‘Maidwell Hall’ and deep-indigo ‘Georg,’ which has a smaller flower but a longer flowering season than most. Later in spring come the large-flowered clematis, of which candy-striped ‘Nelly Moser’ is the best known. ‘Nelly’ tends to fade in strong sunlight so keep her for dappled shade and choose the similar ‘Bees’ Jubilee’ for a hot spot. Among my favourites are cherry-red ‘Ville de Lyon,’ and the glamorous ‘Miss Bateman,’ which has chocolate stamens at the centre of a crisp white flower subtly striped in lime green. ‘Marie Boisselot,’ on the other hand, has larger flowers of pure, dazzling white. Lovers of Wedgwood blue might prefer ‘H.F. Young’ or the double-flowered ‘Countess of Lovelace.’ Most of this group will grow to about three metres and produce a second flush of flowers in late summer. A few varieties will reach only about half that height, among them lavender-blue ‘Lady Northcliffe’ and raspberry-pink ‘John Warren.’ I find the large-flowered hybrids to be the most temperamental of the clematis family, susceptible to clematis wilt, a fungal disease that can cause an entire plant to shrivel and often die within a few days. Planting them deeply (up to 10 centimetres below soil level) is a good precaution; stems below ground will often re-shoot just when you’ve given the whole plant up for lost. The Viticella group of clematis is less prone to wilt, and their vibrant colours and enthusiastic output compensate for their smaller flowers. ‘Etoile Violette’ is deep purple, ‘Rouge Cardinal’ a lush crimson, while ‘Huldine’ displays pearly white flowers with fine purple striping on the undersides. They are among the easiest to prune, too. Cut to about 20 centimetres above ground level in late winter, they will scramble back to a good three metres before bursting into bloom in midsummer. Similar treatment goes for fall-blooming Clematis rehderiana, a species that will drown a four-metre trellis in waves of fragrant, pale-yellow bells, held away from the foliage on dark-brown upright stems. The more refined but unscented Texensis group also bloom in fall, and need no pruning as they die down of their own accord for the winter. Most popular of these are scarlet ‘Gravetye Beauty’ and silvery-pink ‘Duchess of Albany.’ Even in midwinter there can be flowers, and once again it is clematis to the rescue. C. cirrhosa var. balearica opens its subtle cream and red-freckled flowers in January and blooms until March. Given warmth and shelter, ideally close to the house, its promise of spring can raise the spirits during the gloomiest days of the year. The following plants are hardy to the zone number indicated: • Actinidia kolomikta (ornamental kiwi) – zone 5 • Clematis large-flowering hybrids – zone 4 • C. macropetala – zone 6 • C. rehderiana – zone 6 • C. texensis – zone 4 • C. viticella – zone 5 • Euonymus fortunei (wintercreeper) – zone 5 • Humulus lupulus ‘Aureus’ (golden hop) – zone 5 • Hydrangea anomala ssp. petiolaris (climbing hydrangea) – zone 4 • Hedera helix (English ivy) – zone 5 (The cultivar ‘Baltica’ is hardy to zone 4) • Lonicera ‘Mandarin’ – at least to zone 4 • L. x brownii ‘Dropmore Scarlet’ – zone 2 • L. japonica cultivars (Japanese honeysuckle) – zone 4 • Lonicera periclymenum cultivars – zone 5 • Parthenocissus henryana – zone 7 • P. quinquefolia (Virginia creeper) – zone 3 • P. tricuspidata (Boston ivy) – zone 4 • Schizophragma hydrangeoides (Japanese hydrangea vine) – zone 6 • Vitis coignetiae (crimson glory vine) – zone 5 • V. vinifera (ornamental grape) – zone 6 • Wisteria floribunda (Japanese wisteria) – zone 5 • W. sinensis (Chinese wisteria) – zone 5 • Vines that are true annuals, such as sweet peas (Lathyrus odoratus) and morning glory (Ipomoea purpurea), complete their life cycles in one season, so hardiness ratings are not applicable. Some of the vines that we commonly grow as annuals are perennial in frost-free climates. Their zone ratings of 10 or 11 don’t include any parts of B.C., but these plants can be overwintered in a greenhouse or sunny room indoors. They include black-eyed susan vine (Thunbergia alata), cathedral bells (Cobaea scandens), purple bellerine (Rhodochiton atrosanguineus) and Spanish flag (Ipomoea lobata). Master gardener and rose and vine expert Christine Allen is the author of three books. PHOTO Clematis 'Marie Boisselot', John Glover