One of gardening’s great challenges is pruning clematis, if you listen to many of the experts. Gardeners may shy away from growing clematis because they fear that pruning properly is too complicated.

By Barbara Perry Lawton

[This article was first published in The Gateway Gardener June 2015 issue.]

One of gardening’s great challenges is pruning clematis, if you listen to many of the experts. Gardeners may shy away from growing clematis because they fear that pruning properly is too complicated. Don’t let that fear keep you from enjoying one of the most beautiful of all perennial vines.

Although clematis will be more productive, bearing clouds of flowers, if you follow a regime of regular trimming and pruning, you aren’t going to kill the plants by not pruning. An important cultural rule of thumb for successfully growing clematis is one I heard many years ago: Clematis will thrive if you grow it with hot heads and cool feet. In other words, grow the vines in sunny locations but be sure to provide something to shade the root area.

As with all nursery stock, be sure to save the labels—the growers want you to succeed. They will provide succinct sure-fire information about growing the plants. Clematis experts do recommend a first-year practice that most gardeners find hard to follow: In order to have your clematis develop into bushier more beautiful plants over their lifetimes, cut back the vines to a mere five inches in the late winter or early spring of their first year. This will encourage vigorous root growth. You won’t get flowers on the early-bloomers during that first year but the sacrifice is worthwhile.

Clematis vines grow swiftly and, since they can’t support themselves very well, will need some help, a trellis, a bit of hand guidance if they are to perform as you wish. Clematis vines will climb handily over shrubs and small trees. Since they cling to supports with only their petioles, they’re easy to pull down if you want to prune or change the vines directions. Or you can let them wander over a hillside. It’s your garden so you set the rules.

America’s perennial expert, Allan Armitage, grows clematis vines over every shrub in his garden. As he says, “It’s difficult to beat the hybrid vines for color and vigor.”

 

SIDEBAR:

Clematis Groups

To categorize clematis, simply note when they bloom—early in the growing season, mid-season or late summer and fall. As you can see, you really don’t have to do much pruning.

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  C. alpina ‘Stolwijk Gold’, photo courtesy Plant Delights Nursery

  Group One. These early-flowering clematis vines don’t need much more than a light trim. Once they finish blooming, cut back stems that lack flowers or are too long. Old overgrown plants can be cut back nearly to the ground, but don’t do this more than every three years or so.

• Group Two. Clematis vines that bloom in late spring to
  

  C. jackmanii, photo courtesy Walters Gardens Inc.

  mid-summer don’t need pruning except to tidy them up after bloom. Old scraggy plants can be cut back nearly to the ground though you may lose or delay the current season’s bloom.

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  Clematis ‘Princess Diana’, photo courtesy Missouri Botanical Garden PlantFinder, Glenn Kopp

  Group Three. Prune these late summer and fall-blooming clematis vines as far back as a foot from the ground in late winter or when buds begin to swell in early spring. You can prune the very vigorous cultivars all the way back.

Barbara Perry Lawton is a writer, author, speaker and photographer. She has served as manager of publications for Missouri Botanical Garden and as weekly garden columnist for the St. Louis Post-Dispatch. The author of a number of gardening and natural history books, and contributor to many periodicals, she has earned regional and national honors for her writing and photography. Barbara is also a Master Gardener and volunteers at the Missouri Botanical Garden in St. Louis, MO.