Clematis has just completed a banner season, growing up mailboxes, trellis, gutters, telephone poles, fences, boxwoods, and roses. It’s a flowering vine that is easy to grow, super showy, and requires little to no maintenance from the gardener. If you want to grow it but are finding the instructions confusing, start here to learn how to grow clematis and, most especially, how to prune it.
But for fun, let’s start with the pronunciation of the word. Merriam Webster can have the last word on it. Although, even dictionaries differ, so game on for however you want to pronounce it. Click here to listen.
Choosing Your Clematis
Knowing which hydrangea you have is key to taking care of them. Knowing which clematis you’re growing is also key. Clematis are divided into three groups, based primarily on bloom time. If you plan to mix the clematis, choose from the same grouping. That allows for ease of pruning.
Fine Gardening has an extensive list of each group. Click here to peruse through and find yours. If you’re already growing clematis and don’t know the name, watch for a couple of seasons to see when your clematis vines bloom—that’s a tell-all.
Don’t allow this grouping concept to overwhelm you. It’s no different than understanding that most spring-flowering shrubs bloom on old wood (azaleas, rhododendron, weigela) and summer shrubs bloom on new wood (Hydrangea Limelight) and so forth. To keep it simple, watch to see if most of the new growth is on last year’s vine. If so, prune lightly and shape. If most of the new growth comes from the bottom of the plant, you can cut back to 12″ -18″. Below are the groupings.
Clematis are grouped by number or A, B.and C and pruned according to type. This is the biggest thing the gardener needs to know about their clematis vine and which group it is in.
Type One: Blooms early spring on old wood (last season’s wood). These are generally the armandii, montana, alpina. Typically, they require damaged stem removal or thinning every few years, and that’s it. If your clematis is blooming in early spring, you’ll prune right after blooming, so you do not lose your blooms for next season.,
Type Two: Generally bloom in late spring. These are the ‘Nelly Moser,’ ‘Henyrii,’ and other large-flowered clematis. They bloom on old and new wood. Prune late winter or early spring when buds begin to swell. Cut just above the buds.
Type Three: Bloom late summer and only on new wood. ‘Duchess of Albany’ is an example, and these can be cut to the ground in spring, where they’ll sprout back from the crown.
When you purchase your clematis, the tag should tell you which group your flowering vine is in. If it does not, keep the tag for identification and refer to the website above for how to prune.
For step-by-step instructions on pruning, read Lee Reich, master pruner of all plants, how-to here.
You’ll Need a Trellis or a Shrub.
Clematis use their leaf stems to climb. The stems coil around the nearest object like a pea vine, but the leaf stems are short, so they can only wrap around something up to 1/4″ wide. If clematis stems can’t find anything to grow onto, the end stops growing and dies back. If your clematis has gotten bushy and top-heavy, tie up those stems in early spring, as clematis vines are brittle and break easily. Use a wire mesh to aid in climbing when placed near a mailbox, pole, and fence. Use a simple trellis to lean against walls or grow in containers.
Shrubs are an excellent way to provide support, too, especially for clematis in group 3 (which grows on new wood), making pruning simple when it’s time to prune the boxwoods, cut the clematis back to 12″ -18″ as well. The dark green of the boxwoods makes a lovely backdrop for the bright flowers of the clematis. Or mix with climbing roses for a show-stopping scene.
- Sun to part-shade is stated, though most clematis flower more prolifically in full sun.
- Plant with the roots of clematis in a cool, shade-y spot (the shade of nearby shrubs does the job), or if that isn’t possible, be sure to mulch the roots well to help keep them cool.
- The soil should drain well as clematis do not like wet feet.
- Clematis does not want to be moved, so think of this spot as permanent.
- Use a balanced fertilizer (10-10-10) once monthly during the growing season.
It may sound confusing, but clematis blooms for years with little care. Many often ask for the one-and-done plant (meaning little to no maintenance). For those who love the flowers but not the maintenance, clematis fits the bill.
Written by Cinthia Milner, landscape consultant, and blog writer.
B.B.Barns Garden Center serves all Western North Carolina, upstate South Carolina, and Tennessee.