Clambering clematis

Defying the rules? This white clematis has endured increasing shade as the years have gone by, and now grows without any direct sunlight. Though the bloom is sparser than before, it still brightens its shady corner with 6" blossoms every spring.

When I had demonstrated, at the age of about 14, that my enthusiasm for gardening was not just a passing fancy, my parents gave over a section of our yard, about 20' x 50', where I could plant whatever I chose. The area had been planted mostly with divisions of easy perennials from my grandfather: flag irises and cannas and crinum lilies had spread to make large patches.

A large loquat (Eriobotrya) anchored one corner, a coral tree (Erythrina crista-galli) another, and a stately native Torrey pine towered over the south side. My father, in a moment of whimsy inspired by Rudyard Kipling ("dominion over palm and pine."), had planted a palm next to the pine. There was a peach tree, not the best choice in coastal Southern California, and a beautiful lemon guava whose mottled bark and elegant form resemble our familiar Crape myrtle.

I set about to create a jungle, which in a frost-free climate can be easy! I planted tree ferns (Dicksonia, Alsophila), Giant bird of paradise, clumping bamboo, and more palms. Collections of fuchsias and begonias (Rex and cane), along with castor beans, gave a tropical air. Baby tears spread everywhere. I had a few roses, some succulents, odd beds of petunias. Night-blooming jessamine (Cestrum nocturnum), planted just outside my bedroom window, scented the house so powerfully that my mother complained about it.

I once took a bus with some friends all the way downtown to the biggest nursery in the area to buy a tree for the center of the yard. We chose a European white birch (Betula pendula), which we carried awkwardly home on the bus (we had to pay an extra fare). Rather incongruous among the subtropicals, I think it was the only white birch in La Jolla, but it flourished for many years.

But it was the 18 different vines I planted that really created the jungle. That includes the annual ones I grew from seed: Cup-and-saucer vine (Cobaea scandens) and Heavenly Blue morning glory. Fortunately, I happened to remove the latter before it reseeded.

Some of the vines proved rampant and had to be removed almost immediately. Japanese honeysuckle (Lonicera japonica 'Halliana') grew up an 8' trellis, down the other side, and several feet into my long-suffering neighbor's yard in one summer - rooting into his brick path. He beckoned over the fence one afternoon, showed me what it had done, and we cheerfully spent a couple of hours pulling and digging out every bit of it. Passion flower (Passiflora coerulea) showed similar potential and came out after just a few months.

Pink jasmine (Jasminum polyanthum) gave great pleasure for a few years until it, too, showed signs of engulfing a whole section of the yard. The ground-level shoots snaking along and rooting under the Baby tears made us nervous. Bright orange flowers of my neighbor's trumpet creeper (Campsis radicans) cascaded over the fence, delighting the hummingbirds, but the root suckers annoyed the resident gardener.

Not every honeysuckle is rampant! The Japanese honeysuckle (Lonicera japonica) I planted in my garden was an invasive species, and the Giant Burmese honeysuckle could have grown to 30' or more. But Lonicera x brownii 'Dropmore Scarlet' is a moderate growing vine to about 10', bearing bright red trumpet flowers from spring until frost.

I grew up, more or less, and moved away, and my father began removing the vines to make room for other projects. The wisteria quickly came out. One day he called me after spending a couple of hours battling a vine with sharp recurved thorns, and wasn't too surprised when I told him the name, Asparagus falcatus, meant Sickle-thorn asparagus. His real question wasn't what it was, but rather why I had planted it.

Not all the vines I planted were monsters. Botanical Wonder vine (Fatshedera lizei, so named because it is an inter-generic hybrid) provided bold leaves in total shade, branches tied up in a zig-zag pattern against a dilapidated fence, commingling with Kangaroo treebine (Cissus antarctica). A Giant Burmese honeysuckle (Lonicera hildebrandtiana) reached 15' up from a trellis into the Torrey pine. Smilax (Asparagus asparagoides) replaced the Passion flower. Cape honeysuckle (Tecomaria capensis) arched out through the bamboo with sprays of bright orange tubular flowers - more delight for hummingbirds. All of the vines I've mentioned (except the Cissus) are hardy enough to grow here.

One day I got a call from my mother after she went out to check for ripe loquats. The tree was covered with a mass of royal purple flowers! What on earth had I planted?! I was amazed. At some point I had bought a scrawny little clematis vine, probably a Jackmani hybrid, and planted it along the fence to replace the Japanese honeysuckle. My energetic dog had promptly trampled it, and clematis stems are thin and fragile, so I had given it up for dead. Evidently it had resprouted - up a fence, into the tree, across the top, and - joyous to be in the sun - burst into glorious bloom.

This trip down memory lane was prompted by the purple clematis vines that startle me every spring along the east and north sides of my house. Clematis love to clamber up, through, and over other shrubs, vines, and trees, and then pop into bloom all at once. The stems of the deciduous types are thin and barely noticeable when the plant is dormant. As the years go by, the vines can develop quite large root systems, and the growth is almost entirely in the spring and early summer.

So we have a vine which grows 10 - 20' in a matter of weeks, and then rewards us with a mass of flowers. The growth is lightweight and readily supported on a simple trellis, or can grow up onto nearby plants. A classic pairing is a clematis growing into a climbing rose. One of mine meanders through a hedge of Heavenly bamboo (Nandina domestica), with nearly identical foliage. Another sprawls across a low evergreen hedge of Sarcococca.

There are hundreds of varieties of Clematis, grouped by when they flower. A couple are evergreen, notably C. armandii. Somewhat rampant, it is the first to flower, with white lemon-scented blooms in late winter; there are good examples in the Carolee Shields White Flower garden at the UC Davis Arboretum, and on an arbor in the Oakshade shopping center in South Davis.

Next are the deciduous species and hybrids which flower in late winter and early spring on last year's growth ("old wood"). Varieties of C. montana, these are abundant-blooming and tolerant, with flowers scented lightly of vanilla in white or light pink. They can be pruned back hard right after the bloom for size control.

Most clematis bloom either in spring, or through the summer, on new growth ("new wood"). In California they bloom a month or more ahead of the descriptions in publications from England or the northeast. These types need either long days (12 hours) or very long days (14 hours or more) to set flower buds, which means they start to form buds after March 21. The flowers then develop at varying speeds depending on temperature and variety. So some give an intense bloom in May to early June, while others bloom from June into the late summer. In either case, you can cut them back hard in the winter. Some later-blooming types such as C. viticella hybrids are especially free-flowering and vigorous.

You don't have to prune clematis at all! The literature is very confusing. The purpose of pruning is to reduce the overgrown tangle and keep them from blooming further and further out on the stems (like, say, on top of a loquat tree!), lest they get bare at the base. If that doesn't bother you, leave them alone. If you don't know what kind you have, don't prune it until you know when it blooms.

Keep their roots shaded and moist, but the tops can grow in full or partial sun. Add lots of organic material at planting, and place them deep in the hole (a rare case where we plant deeper than the plant is growing in the pot). They don't need much support, training, or fertilizer. Even the seedheads are attractive. There are native species which are adapted to lower-water landscapes. One evergreen shrubby species is being marketed as a ground cover. Recent introductions include dwarf types suitable for containers; I've even seen some types sold as house plants, though I don't think they're very sustainable indoors.

Top of Page