A Proclivity for Clematis

August 29, 2017Margaret Ransohoff

If you visit my garden in summer, you will observe that I have clematis growing in every corner of the landscape. It is probably my favorite perennial and I have devised many ways to take advantage of the color, shape and dimension that they provide. While I’m not the person to ask for advice on pruning or identifying the cultivars, I do have years of experience growing them in our region and can suggest ways to get the most out these gorgeous, hardy plants.

The first rule for growing clematis is to find a location where it receives plenty of sun, but has shade at the base. They also like moisture, so don’t place it in a dry spot under the eaves or too near the base of a large tree. Because they don’t have tendrils or twining stems, they use their leaf petioles to attach themselves and must grow on a structure that will accommodate this. Additional support is often needed for these plants to achieve a desired effect. In the spring when the vines begin to climb, decide where you want them go, provide sturdy support, and continue to guide the vines by hand for a few weeks until they are in place. This is what I find to be the most important step in achieving maximum beauty from your clematis!

When I began growing clematis, I placed them in the usual spots: on lampposts, trellises and fences. Over time, I realized that with some extra effort in early summer, the plants could be trained and shaped to better fit and enhance these locations. My first was this Jackmanii, an old fashioned cultivar that blooms heavily and is easy to grow. The plant has become so dense that I now split off a section and train it to grow along the nearby railing, tying it at about one foot intervals. The lamppost also has several strings from bottom to top to support the heavy vine; without this, it becomes top-heavy and falls away from the lamppost. My other Jackmanii outgrows the ironwork trellis, so I split the plant when it reaches about three feet and train part of it to grow up the copper downspout. Because the downspout is smooth, the vine must be tied at several points to keep it growing upward.

Some clematis need manipulation as they grow to look balanced and cover the desired area. This vigorous Ernest Markham is planted at the outer corner of a fence. When it reaches the top edge, I gather the vines into two sections and then train them to grow in opposite directions. This looks much better than letting it grow into a large mass that flops over to the inside of the fence.

I longed for colorful vines against these stone walls, but unlike ivy, clematis wouldn’t climb this surface. Using H.F. Young, a vigorous twelve foot variety, I came up with a method that would allow the plant to cover the stone. For the one on the left, I use tall stakes to guide the plants up to a string lattice that I wove through the open stonework. When they reach about five feet, I coax them left and right on the strings so that the vines will spread evenly. This requires lots of time and fussing, but I love the results. In the photo on the right, you can see a clematis climbing up a flat stone wall. To achieve this, I attached a foot wide strip of plastic garden netting to small nails that were originally put around the stone arch to support Christmas lights. Here again I use tall stakes to get the vines up to the net and then let them climb on their own. The netting is not very noticeable, so I can leave it up in the winter. It’s important to select a variety that grows tall enough for the location.

Rose pillars or similar structures look great covered in clematis and add colorful, vertical elements to this border. I planted several varieties with different bloom times on each pillar to prolong the display. This also makes the pillars look dense and luxuriant.

The newest method I’ve utilized for adding more clematis to the garden is to plant them underneath azaleas or other low shrubs; they grow up and through the branches and then cover the shrub in flowers. Because clematis “like their heads in the sun and their feet in the shade,” they grow nicely when planted this way. As the vines reach the top of the shrub, I arrange them by hand to get even coverage. This trick will give you an extra month of color from an azalea, tree peony or any other shrub that grows in sun. The mix of vines shown here (I don’t recall the names) are only two years old, so I expect even better results in the future. A patio size clematis works best.

I also get an extra month of bloom from my wisteria vine by augmenting it with clematis Avant-Garde, a ten foot vine with petite semi double blooms. It climbs easily up and through the wisteria stems and needs no additional support or guidance.

My most recent clematis acquisition is this groundcover clematis called Sapphire Indigo, and it is outstanding. I planted it in a clump of hellebores last year and it has already smothered their leaves in deep blue flowers. It started blooming in June and is still in flower and sending out buds in August. Remarkable. This is a totally care free plant with no stakes or ties needed; just let it ramble and guide it if you’re fussy. I’m busy dreaming up new locations for this one!

Fall is an excellent time to plant clematis. The plants that remain at the nurseries may look tired, but unlike those bought in spring, their roots have had an extra summer of growth. Plant them now and they can establish themselves in your garden and be ready to thrive next spring. And they’re probably on sale! I can’t think of a perennial that adds more color, drama or dimension to the garden than clematis and there’s no better time to than now to add a few to your own landscape.