Clematis a flowering vine not to be feared

Purple Clematis Photo by Karen Lawrence

Dr. Bob Gilbert Columnist

Bob Gilbert

I started off on the wrong foot with flowering vines.  Early on I attended a horticultural lecture on native plants and was introduced to a native Begonia named Cross Vine.  I could hardly wait until I found one for sale.  About the same time, we constructed a trellis and overhead structures that needed a green growing covering.  We were talked into planting Wisteria. The Wisteria required untold hours of pruning attempting to control its growth.  As it matured it wrapped itself around the vertical supports so vigorously that the supports began to twist in spite of the fact they were cemented in place.  Meanwhile the Begonia reached the top of a very tall mature pine tree while producing attractive yellow orange tubular flowers in the spring that were equally as pretty on the ground as well as on the vine.  I then discovered it traveled horizontally on top of the ground and by underground branches. I learned first-hand the term stoloniferous. We found it many yards away from the original planting.  It took years to get rid of both vines.  I used to tell visitors not to stand still too long by either one.   I bet there are still remnants of the Begonia present at Smith Gilbert Gardens 50 years later. It might even be in the next county by now.   No more vines for me which in retrospect was a shame as I missed the pleasures of the Queen of vines, Clematis.  Now I enjoy them in other’s yards only because I live in the woods with very little direct sunlight.

On a rare recent drive to town not long ago we had to pull off the road to admire a Clematis in full bloom growing well on a pole.  Karen Lawrence’s photo of it does it justice.  I am not familiar with all the many varieties so I cannot accurately tell you it’s varietal name.  Take the photo to a good nursery and I will bet they will know it.  It looks familiar.

Clematis (Klem’-a-tis) is a genus of 300 species within the buttercup family.  Most available selections are cultivars and new ones come on the market regularly. Also we have a couple of native species.  They generally are referred to as woody vines.  Most of the cultivars were produced by selective hand pollination techniques with the seedlings used for vegetative cuttings.   I have several friends that do that at home rather successfully.

Clematis is Greek for climbing plant.  Garden varieties started to become popular in 1862 with a selection Clematis x jackmanii.  It is still on the market and remains popular.   Almost all selections were originally from China or Japan.  The British have named a species of theirs “Traveler’s Joy.”

The genius is composed mostly of woody climbing vines with a few that are shrubs.  Species found in the tropical climates are often evergreen compared to the temperate zone deciduous species. All  are easily grown.  There is an old adage “Clematis like hot heads and cool feet.”   So full sun and ample mulch is important.

Different species bloom at different times of the years and from different parts of the plant.  This creates some confusion about pruning as you do not want to eliminate the blooms. I will try to simplify a pruning guide. Spring bloomers flower on side shoots from the previous year’s stems, summer and fall blooming varieties bloom on the end of new stems and repeat, or twice bloomers bloom from both.  Most Clematis plant labels at a nursery will indicate which group the specimen is in.

The objectives of pruning are to eliminate dead portions, maximize flower production, and manage plant size.  Often this information is organized into three groups based on bloom times:

Group 1 – Early blooming April and May on last year’s stems, prune after blooming only if needed

Group 2 – Flowers from old as well as new wood, selective light pruning after flowering

Group 3 – Flowers in late summer on new wood in the fall, prune heavily in the spring if necessary

If you do not know the name of your plant by observing the bloom times and bloom location you can after a year know which group our plant is in.

We have two native Clematis worth knowing about.  Clematis virginiana or Virgin’s-bower is often found at woods edge.  It produces large numbers of one-inch wide white flowers.  It is easily grown from seed and is often used on fences.  In the fall, plumes of feather like seed pods are especially noticeable.

The less common native is Clematis pitcheri often called Purple Leatherflower, Purple Clematis, Bellflower and Pitcher’s Clematis.  It is a semi-woody vine that can grow to 10 feet.  It is not a heavy bloomer but the purple nodding blooms are unique.  It would be a great vine to let grow on an evergreen small leaf shrub like ilex crenata.

Do not be afraid of Clematis escaping, they stay put.

Dr. Bob Gilbert, co-founder of Smith Gilbert Gardens in Kennesaw Ga.

Karen Lawrence is a professional horticultural and wildlife photographer from Franklin NC