Crazy For Clematis

Crazy For Clematis!

It's true: Our Southern Great Lakes region is absolutely crazy for clematis! Image licensed through ©iStockphoto.com/Jan Tyler, photographer I can easily bet that whether one goes to any neighborhood, old or new, rich or poor, there is going to be a clematis vine growing on a trellis or arbor somewhere in any given neighborhood.

While there are a few shrub clematis, this article is all about the clematis most of us are familiar with, the perennial climbers.

Clematis are the tried-and-true perennial climbers for our region. There are many cultivars, some hardier than others. If you know what variety you are growing, pruning will not be a problem. A good place to start with this plant is to list the pruning techniques and some of the varieties associated with them:

Clematis are divided into 3 main groups, as far as pruning goes. They are grouped in Classes 1, 2, and 3:

Class 1

This group flowers on old wood, or the previous season's growth. A few of these are not as hardy as other clematis in our region. They flower on old wood, mainly in the spring. They are pruned right after flowering, and only require hard pruning once, when initially planted, to about 12 inches. Otherwise, prune lightly, if at all, and only for shape and maintain size or to remove dead or broken stems:

C. alpina 'Constance': Dark red, shade tolerant, hardy throughout the region

C. alpina 'Helsingborg': Deep blue, shade tolerant, hardy throughout the region

C. alpina 'Francis Rivis': Deep blue, shade tolerant, hardy throughout the region

C. macropetala 'Markham's Pink': Pink flowered, doubled, hardy throughout the region

C. macropetala 'Maidwell Hall':Deep blue, shade tolerant, hardy throughout the region

C. montana 'Wilsonii': Late Summer to early Fall blooms. Chocolate scent. Zone 6, sheltered

C. montana rubens: Pink, stems have reddish tint. Vanilla scent, Spring blooms. Zone 6, sheltered

Class 2

This group is twice-flowering, as a rule, with larger blooms in late spring to early summer and smaller sized blooms in late summer to early fall. These bloom early in the season on short stems produced on old wood. The second flush of bloom later in the season is on new wood. This is the category that scares some gardeners away from growing this class of clematis. Pruning is not that complicated, the worst that can possibly happen is you won't get too many flowers if you overprune. In fact, you could get away with not pruning at all, except then the blooms would be higher up on the stem instead of having a full flush of blooms. In the spring, first prune out any broken, dead, or weak stems. Then, about a fourth to a third down from the top, prune to above two good buds on each stem. That's it, other than pruning hard for the first two years, back to about 12 inches, so that the plant can get established. Here are some varieties to consider:

C. hybrida' Arctic Queen': Double white, hardy throughout the region.

C. hybrida 'Nelly Moser': Pale mauve with a central line of deeper lilac pink, hardy throughout the region.

C. hybrida 'Niobe': Deep wine red with yellow stamens, hardy throughout the region.

C. hybrida 'Guernsey Cream': Creamy white, hardy throughout the region.

C. hybrida 'Lady Londesborough': Pale pink to silvery mauve, lightly scented, hardy throughout the region.

C. hybrida 'Duchess of Edinburgh': Double white, hardy throughout the region.

C. hybrida 'H.F.Young': Wedgewood Blue, white stamens, hardy throughout the region.

C. hybrida 'Haku Ookan': Deep violet blue, white stamens, hardy throughout the region.

C. hybrida 'Lord Neville': Deep blue, wavy-edged, hardy throughout the region.

Class 3

This class blooms on new wood, so whack away at it! Seriously, this group blooms on current growth, and some of the varieties that I am listing would technically be in Class 2, but for simplicity's sake, treat them as class 3: Prune early in the Spring, and keep the pruning to about 12 to 18 inches above the ground. Do this heavy pruning every Spring. Prune so that the first two strong buds at this height on the stems are left. These are vigorous growers, so be sure to prune them hard at least the first two years that you grow them. As with the other classes, this promotes good root development:

Clematis x jackmanii 'Jackmanii': Deep pruple, popular beyond all measure, hardy throughout the region.

Clematis x allanah 'Allanah': Deep red, ruby blooms, hardy throughout the region.

C. viticella 'Blue Angel': Sky blue with wavy edges, hardy throughout the region.

C. hybrida 'Comtesse de Bouchard': Medium pink, hardy throughout the region.

C. terniflora: 'Sweet Autumn Clematis': Small white fragrant flowers. Fall blooming. Hardy.

C. vitecella: 'Etoile Violette': Violet purple, hardy throughout the region.

C. vitecella: 'Madame Julia Correvon': Deep red, hardy throughout the region.

The general rule with clematis is to provide moist, not boggy, organic soil. They are heavy feeders. It is a good idea to fertilize them with a good organic fertilizer or organic rose food, after pruning. They do well in the sun, and the ones that are stated as shade tolerant require at least morning sun. None of the clematis will thrive in full shade. An old saying with clematis is: "Keep their faces in the sun, and their feet in the shade". Be sure to apply mulch to the base of the plants to keep their feet cool.