Over the Garden Gate: Clematis – Queen of the Vines
Martha Murdock, in a 2017 Over the Garden Gate article, made a picturesque observation concerning a fundamental element of gardening: “[V]ines are the threads that weave [a garden] together. They can be graceful loops of color and texture, leading the eye from place to place. They can dress up arbors, fences, pergolas, columns, trellises and even other plants. Vines can enhance almost every garden design.”
One of the most beautiful of these vines is the clematis, often called the “Queen of the Vines.” Their flowers possess a grace and eloquence few plants can match. Containing both vines and herbaceous plants, the genus clematis contains species that can be anywhere from 6 inches to 40 feet tall with flowers as tiny as thimbles or as wide and flat as a salad plate. A few forms are fragrant, and the large hybrids come in all colors with the exception of truly yellow or orange. For a gardener with an overactive collecting chromosome, there is no better genus with which to become obsessed.
I must agree with that description as I am such a collector. Repeatedly, I have fallen in love with clematis’ pretty faces. Also, unfortunately, I have killed my fair share of these beauties. When I began my Master Gardener’s training last September, I decided that I should not be content with a single season of bloom; now was the time to research just how to produce long-lived healthy plants with optimal flowering. It was time to learn the clematis’ special needs to share with readers.
Spring is the optimal time to plant species of clematis that flower in late summer, fall and winter. The prime time to plant species that bloom in the spring and early summer is fall. Ideally, clematis should not be planted when they are in flower.
Clematis is a rule-breaker when it comes to planting. Typically, plants should be placed so that the top of the soil in the ground is the same as it was in the container and planted directly in native soil. But clematis are special, and they want special treatment. These step-by-steps to growing clematis will ensure success.
1. Prepare for planting your clematis. Soak the plant by sitting the pot in water for an hour. While your clematis is soaking, prepare the ground. Clematis like deep, fertile, moist, well-drained soil, so dig well to loosen the earth and fork in organic matter (such as compost).
2. Position the clematis. Lean the clematis at a 45-degree angle towards the wall or fence where you want it to climb. Plant large-flowered cultivars 2 to 4 inches below the level they were in the pot. Bush types should be planted shallower, but still planted just slightly below soil level. The clematis needs at least 2 gallons of water immediately after planting. Afterward, keep the soil moist but not soggy Because clematis needs cool roots, a 2-inch layer of wood chip mulch should be applied. Shallow-rooted plants could also be planted around the base of the clematis to provide shade to its roots. Clematis is slow to become established during the first year or two. With adequate moisture and sunlight, though, it should take off by the second or third season
3. Train the clematis. Provide a structure, such as a trellis or pergola, for the twining stems to coil around as the plant climbs. It is important to remember that clematis like to wrap their petioles (a petiole is the little stem that attaches the leaf to its main branch) around other stems or structures of ½” diameter or less. Some help from chicken wire, wire wrap, or vine nails will be necessary when the vine is young.
Once planted, pruning is the next step. This is the step where most people freak out. It helps to know that, left unpruned, clematis vines become overloaded with decrepit stems that produce few flowers. So now is the time to cut the plant back to about two leaf buds, a height of 18 to 24 inches. This will encourage branching and the development of from 3 to 5 stems. Though this seems hard right now, you want your clematis plant to worry about roots, not flowers or stems.
After the first year, pruning is according to type as determined by bloom time. For pruning purposes, clematis are placed into three different pruning groups:
GROUP ONE consists of all the early-flowering evergreen species and their cultivars. They are all early to mid-spring bloomers. Prune them after the main flowering period has finished.
GROUP TWO consists of all the old-wood flowering, the double and semi-double large-flowered cultivars and the mid-season large-flowered cultivars. Prune them after the main flowering period has finished.
GROUP THREE consists of the large-flowered late blooming cultivars. These all bloom on the current season’s wood and should be pruned in the early spring.
Other considerations include hard pruning and light pruning.
Hard pruning refers to cutting all the stems within a few inches of the soil, being sure to leave a good set of buds. Hard pruning stimulates growth and is usually done on young newly planted vines during the first spring after planting. This is recommended regardless of the blooming time of the clematis. Hard pruning can also be done early in the spring on late bloomers (group three above). This will actually increase the number of blooms.
Light pruning is the safest and suitable for all types of clematis. In the spring, start with the removal of winter-killed stems. During the growing season cut back the ends of the stems that have finished blooming. This will help keep the plant in control and remove the spent flowers (deadheading). Deadheading will also stimulate continued blooming.
No matter which pruning method works for you and your vine, remember to give your clematis a half-strength dose of your preferred fertilizer after each pruning manipulation. Clematis are heavy feeders, and it is necessary to combine appropriate pruning with a fertilizing regimen to get your climber back into bloom as quickly as possible.
In Gardening with Clematis, Linda Beutler claims that all shrubs and trees were put on the planet to support and enhance clematis. I would have to agree. No matter what color combination you want to explore, no matter what cultural niche needs filling, no matter what plant in your garden looks as if it could use a friend, there is a clematis waiting for you. Probably more than one!
My hope now, is that with your newfound knowledge, you will seek clematis for your garden that are new to you and that you are now emboldened to use in them new ways. Plant them confidently, ignore the setbacks, applaud their successes. Create a clematis garden that is innovative, that will challenge you, and that you will love.
Lorraine Beattie is a Master Gardener Apprentice with Penn State Extension, Beaver County.
This article originally appeared on Beaver County Times: Over the Garden Gate: Clematis – Queen of the Vines
