Clematis

Clematis Think you’re running out of space in your garden for new plants? Think again. Think UP. One of the loveliest vines in the plant world (as a matter of fact, referred to as the "queen" of the climbers) is the one and only clematis. Referred to as either CLEM a tis or clem A tis, it is definitely a "garden worthy" addition for everyone. Easy to grow, once you know its likes and dislikes, you can enjoy three seasons of flowering beauty. The clematis is a member of the Ranunculaceae or Buttercup family. The clematis flower forms are wide-ranged and varied. Some are bell-shaped, others resemble tulips, pointing up or down, many wavy or frilly, some double, still others have sharply pointed petals resembling a cactus dahlia. Many hybrid cultivars range from two to six inches across and bloom as singles, or single and double on the same plant. Most are repeat bloomers if pruned at just the right time. Their growing heights also have a wide range, from scramblers running along the ground, to a height of only a foot or two, all the way up to 30 feet. Many gardeners believe you need to grow these beauties on a trellis or some other manmade structural form. Not so. They are not fussy in this department either. Some of the most perfect hosts for your clematis’ are roses, camellias, choisya, hydrangeas, pieris, lilacs, elderberry, evergreen and deciduous trees, and just about any other shrub you can imagine to assist them in their upward journey. The only caveat to their chosen counterpart would be to avoid placing them with a host that needs regular and significant pruning, since most clematis forms latch on to their neighbor through the use of tendrils growing from their stems which attach to nearby branches or anything else in proximity. Don’t stand too close for too long! Clematis grow in either shade or sun but not in "deep shade". Some varieties prefer more sun than others. However, they all like to have their roots kept cool. This can be accomplished by planting them behind a shrub or some other item which will maintain a cool soil temperature. And, they all like moisture, (but not the root-rotting kind) especially the first year after planting in the garden. When transplanting from their plastic container into the garden, it is important to first unattach the stake that most growers staple to the pot. It also benefits the plant to prune to 6–8 inches of stem. This encourages the plant to send up new shoots and multiple branching. Clematis should be planted rather deep (an inch or two deeper than their pot depth) in a generous sized hole, with compost mixed in. No fertilizer until there are signs of new growth. The renowned clematis collector Brewster Rogerson recommends a "rose type" fertilizer (5-10-10) in the Spring. If clematis’ are fertilized when budded, it encourages them to open their buds all at once. It will be a spectacular show, but will not last as long. It is recommended that you forego fertilization at that stage until after bloom. Then, trim the plant back by about 1/3 and fertilize, and in many cases you’ll have another spectacular show in about 6 weeks. THE MOST IMPORTANT THING you need to know about clematis is their pruning requirements. Prune at the wrong time and you won’t have flowers. The pruning key is "easy" once you know the codes. All clematis are classified for pruning as 1, 2, or 3 (some growers use A, B, or C, which is the same as 1, 2, or 3). Pruning category 1 (or A) DO NOT PRUNE unless you need to for plant size control. These are generally the very early bloomers putting on their show in late winter or early spring. Category 2 (or B) are the midseason bloomers, spring to early summer, and will bloom on old and new wood. If you prune before their bloom you will interrupt their cycle and cut off all upcoming flowers. Better to wait until "after" the first bloom to do any pruning. Pruning category 3 (or C) are the late season bloomers. That means bloom time from late summer to autumn. Those need to be "hard pruned" to about 3 inches from the ground in late winter or early spring. For those of us with a passion for clematis, there is a marvelous book by Mary Toomey and Everett Leeds titledAn Illustrated Encyclopedia of Clematis. The photos alone are worth the price of the book. However, you won’tfind ALL varieties contained therein, since new ones are developed constantly. WSU Clark County Extension, 1919 NE 78th St, Vancouver, WA 98665, 360-397-6060, Contact Us