How and When to Prune Clematis Vines to Boost Flowering

Often growing with little care in the right spot, clematis vines will bloom best when trimmed correctly at least once a year. Knowing how and when to prune clematis can do a lot to keep your vines colorful and healthy, year after year. This guide covers pruning the three main groups of clematis, based on the time of year they bloom.

Clematis Groups

A long-time favorite in American gardens, clematis are perennial, mostly vining plants that are categorized into three groups. Each group grows and blooms somewhat differently, so it’s best to know where your clematis fits before you start trimming your plant.

Group 1

You can expect to do very little pruning in this first group aside from removing broken, dead, or out-of-place vines. Clematis in this first group produce blooms on old vines, so pruning should only be done after their second year, if at all.

Bloom Time: Spring.

When to Prune: Shortly after blooming.

How to Prune: Focus on just reshaping, cleaning, and deadheading the vines, which allows the plant to continue growing and developing flower buds for the next season.

Group 2

Pruning Group 2 clematis is a little more involved than Group 1 because of the repeat blooming, but it keeps plants looking their best. This group of clematis produces flowers on the previous year’s growth and a second flush of flowers on the current year’s growth. They flower twice in a single year under ideal conditions.

Bloom Time: May and June, and again in late summer.

When to Prune: Late winter or early spring as buds begin to swell, and again after first set of blooms has faded.

How to Prune: Remove any broken, unruly, or dead vines from the plant. Then cut back a third of last year’s growth to about 12 inches from the soil. Leave at least one strongly growing bud on each vine. Group 2 clematis can also benefit from a second round of pruning after the first set of blooms has finished. Deadhead seed pods to direct the plant’s energy into a second wave of flowers later in the season.

Group 3

Group 3 clematis are exceptionally easy to prune. Clematis of all kinds grow at a surprisingly fast rate, and Group 3 plants bounce back quickly. A popular example is Clematis jackmanii (shown here), which has large purple flowers.

Bloom Time: Mid-summer through early fall.

When to Prune: In late spring, just as the buds begin to swell.

How to Prune: Cut back these plants entirely each year to allow for a huge amount of new growth that’ll bring new flowers. Prune all the vines down to about a foot above soil level.

Clematis Care Tips

As with all plants, when living leaves, branches, and stems are removed from the plant, they lose nutrients. To counter this loss of nutrients and boost your clematis in spring as growth resumes, apply a low-nitrogen fertilizer followed by a balanced fertilizer every four weeks throughout the growing season. Clematis are heavy feeders and appreciate the extra supply of nutrients that allows them to bloom to the best of their ability.

Each spring, mulch around the base of the clematis. Mulch helps hold moisture in the soil and keeps the ground cool. Apply a 3- or 4-inch layer of composted bark chips, shredded bark, or another organic mulch, and remove any weeds that might compete with the clematis roots.