Versatile and manageable, clematis vines delight with their colorful flowers and attractive foliage. A favorite with generations of gardeners, clematis vines can be grown as a backdrop to perennials—or let the vines scramble over a shrub or along the ground. Clematis can be grown on a fence, trellis or in a container. Thanks to modern breeding efforts, clematis are available in an array of flower colors, forms and bloom times. Perennial vines, clematis come back year after and year and are usually pruned once a year. When selecting clematis vines to buy online, factors to consider include hardiness zone, sunlight requirements, flower color and form.