How to prune that beautiful Clematis

Published 8:28 pm Wednesday, October 15, 2008

Q: We have what I’ve been told is Clematis growing in front of a block wall on the side of our house. This plant seems to be out of control and needs cutting back if that is possible. We know nothing about how and when to do this. Can you give me help in this area?

A: Clematis is a very popular plant for homeowners for several reasons. Not only is the Clematis simple to grow and fairly problem free, it also adds color from its beautiful flowers and provides a vertical dimension to the landscape.

The question about proper pruning often arises, with many complex methods offered, depending on where you look. The problem is that many of these differing methods lead to much confusion. Perhaps the following pruning suggestions will enable you to encourage flowering and good plant growth for the variety that you are growing.

Some Clematis bloom on last year’s growth, while others bloom on new growth. This fact about Clematis is what normally causes the confusion of when and how to prune. Knowing the variety of your Clematis is the key to the proper pruning time and the amount to prune. If in doubt, don’t prune before flowering.

Most large-flowered Clematis varieties bloom in the spring on old growth. These plants should be pruned lightly in the late winter or early spring. Pruning should start from the top down, removing only dead or damaged stems to the highest pair of healthy buds. Varieties in this group may be only 2 or 3 feet above the ground, depending on the age and vigor of the plant.

Small-flowered summer or early fall bloomers flower on the new growth. These plants need to be pruned hard at the end of the growing season or in the early spring just prior to new growth. On these varieties, pruning should start at the bottom and work upward from healthy pairs of buds located 15 to 30 inches above ground. Remove all old top growth that did not die naturally over the winter. Many of these plants will add 6 to 10 feet of growth during one season.

After pruning, be sure to water, fertilize and mulch your Clematis. You may also want to tie the stems to a support to prevent wind damage.