Pruning clematis: It's complicated...

Clematis vines, like most roses, grow well in our part of the state. There are more than 200 hundred species, with many cultivars.

These plants are not particularly disease prone and they like the well-drained soils and fairly neutral pH. The plants prefer sun on their tops and shaded roots.

Because they are heavy feeders during the summer, use a balanced fertilizer about once a month to help keep them in optimal condition. The problem is knowing how to prune them, so that they look good and stay healthy. There are some rules about pruning the different varieties that should be followed if you want their best bloom.

Every spring when blooming begins, I start thinking about pruning the varieties of clematis I have in my garden. It helps to know there are different varieties that are pruned at different times of the year and in different ways.

When I first started growing clematis, I was not careful about recording the varieties that I purchased. For years I had one vine that never seemed to bloom until I figured out that I was pruning it at the wrong time of the year and in the wrong way.

Here are some general instructions for identifying what kind of clematis you might have and how to prune them. The information is from the “Clematis” Bulletin from the Spokane WSU Extension Master Gardener site and from Lee Reich, a well-known garden writer, in his article in Fine Gardening Magazine.

The key to knowing when to prune is being alert to when the vine blooms, according to Reich, although there are some variations depending on the variety, which is where it becomes important to know the name of your cultivar too.

The “Clematis” Bulletin has an extensive list of clematis vines with instructions about when and how to prune them. I haven’t gotten any better at keeping track of how to care for new vines. I won one this spring at a gardening conference, but since it didn’t have a name or instructions for pruning, I’ll have to wait a year to find out how to prune it right.

There are other reasons to prune the vines. The vines can get overloaded with non-blooming stems, or out of reach and too high to see, or top heavy, which can pull the whole plant over. Pruning is good for the vine, stimulates new growth, limits disease and makes the vine more attractive.

More about clematis next week.