Authority Raymond Evison gives low-down on the high-climbing vine Climbing evergreen or deciduous clematis clamor over garden fences, trellises, trees and shrubs, but a large garden is not necessary to grow these versatile vines. Containers of blossoming clematis enliven small decks and patios or graciously greet guests at front doorways. 

There are more than three hundred clematis species and cultivars, so weeding out the best varieties for our Northern California gardens could be daunting. Fortunately, Raymond Evison, world-renowned clematis authority, takes the mystery out the selection process and also shares his expert knowledge on how best to grow clematis in containers. 

"Growing clematis in containers is sometimes thought of as being modern or new, but people did it back in the Victorian era," says Evison. His picks for our climate include, late spring flowering C. Anna Louise™ which sports glistening 6-inch diameter violet blossoms, and, C. Josephine™ bursting into bloom in early summer with lilac colored double petaled, 5-inch wide flowers. Both varieties are deciduous and last well as cut flowers. 

Evison encourages home gardeners to buy younger, smaller plants. However inspect these 5 and 6-inch clematis carefully. "Make sure there are plenty of stems, three to four stalks coming from the base. Buying large plants is fine, you're buying time," says Evison. 

Small plants are not to be planted in small pots however. Both C. Anna Louise™ and C. Josephine™ require large containers. The reason: these smaller plants grow to 8 feet, and while the foliage and flowers enjoy full to part sun, clematis roots must stay clear of it. Evison recommends large stone or terracotta pots that are at least 15 to 24-inches in depth and diameter, the bigger the better. Plastic containers are discouraged, as plastic does not insulate the plants' tender root system from the heat of the sun. 

Growing clematis in association with other plants further protects their fussy roots, especially when planting in hot southern exposures. Evison suggests under-planting clematis with shallow rooted bedding plants. "We take this lesson from the wild, he says. Clematis growing in the wild, both in China and California, root themselves under a rock or underneath the shade of tree or shrub." 

During summer, under-plant clematis with annuals such as petunias, lobelia, impatiens or dwarf dahlias. At the season's end, replace the bedding plants with shallow rooted perennials, like winter flowering heather, tulip bulbs or the gray foliage of artemisia. Placing a stone slab over the root area is an alternative to under-planting. 

All plants thrive in good soil and drainage; clematis is no different. Use premium quality potting soil, and create excellent drainage by layering small pebbles in the bottom of the container. 

Here's one of the most important lessons to take from Evison: plant clematis an extra two inches deeper than it was planted in its' original container. Not only does this help the plant establish more easily, but the plant will also grow a crown of buds below the surface of the soil. Buds below soil level make it possible for the clematis to grow back if, for instance, pests or mistakes in pruning cut off the top of the plant. Furthermore, large flowered cultivars that are susceptible to clematis wilt (a disease that kills the plant practically overnight) will regenerate themselves. 

Caring for newly potted clematis is quite simple. Clematis are thirsty plants, so make sure to give them plenty of water. Evison suggests one gallon of water every other day, especially if planting in warmer weather -- late spring or early summer. 

Additionally, clematis are light feeders, so only feed established plants one time per year during early spring. That's when clematis need additional nutrients to grow and flower. Evison suggests an all-purpose fertilizer, or rose or tomato fertilizers. Careful not to use high nitrogen fertilizers, as the plant will produce lots of green growth but few flowers. 

Clematis vines need something to climb up and cling to. Train them to grow upward by tying their vines to a trellis purchased at the garden center or create a teepee shaped support with bamboo canes. A teepee is easily made by deeply inserting four 8-foot bamboo canes in each quarter of the pot. Bring the canes together at the top, and fasten them together with twine. 

Alas, we must talk about the dreaded pruning of clematis. There are three pruning groups, but thankfully Evison has made it pretty simple. "The first spring after you plant, no matter what pruning group, prune it back to 12-inches above ground level. This will make it bushy at its base, which very very important," he says. 

Both Anna Louise and Josephine belong to pruning group two. "In February or March, look at the plant and cut out any dead or weak growth. Cut it back to a strong pair of leaf axle buds. These buds are swelling and they very clearly denote, this is where to prune," states Evison. 

Containers of clematis are found ground in the smallest of gardens, but bring a wealth of color and drama. The varieties suitable for Bay Area gardens are sure to be a focal point in your "neck of the woods." As for Raymond Evison, he continues to search the world's forests for wild clematis that thrive out of their native habitats. To date, this gentleman is responsible for discovering and introducing 70 clematis species and cultivars to the gardening world.