Clematis is a subject that a gardener ought not to study too much, or they may be too frightened of trying to grow it.
You may read that it is difficult, particularly about pruning, slow to get started, and perhaps not hardy where you live. However, in most cases and places, the opposite is true.
Strange to say, the many kinds of Clematis (correctly pronounced CLEM-a-tis) were better appreciated by gardeners of the past than by the present generation.
After the Jackman variety (really now considered a species) was introduced in Europe in 1864, breeders created hundreds of other new types widely planted in Europe and England.
Interest diminished, as did the number of varieties, but Europe still has far more kinds than we have. More than 50 kinds of Clematis are available in the United States now.
Of these, the Jackman still stands as the most versatile and popular.
A Revival Of Interest In Clematis
A revival of interest in Clematis here in recent years is timely, for these vines, especially the significant flowering kinds, are ideally suited to modern planting needs.
They are refined, making plants of controllable size and furnishing blooms starting in late May or June and lasting almost all summer.
They will adorn fences, railings, posts, or arbors with carefree grace. They never get out of hand and do not demand much attention. The foliage is attractive, and the flowers offer an exciting variety of colors.
Flower arrangers often prize even the seed heads. Some authorities consider the clematis hybrids the most beautiful of all flowers.
Hardy Large-Flowered Clematis Kinds
Most large-flowered kinds are as hardy as peonies. They can be grown in Canada, Alaska, the northern plains, New England, across the prairie states, mountains, and almost anywhere except in the too-mild climates of Florida and the South.
There the large-flowered Clematis suffers from heat and seldom lives long.
The South can grow other kinds. The sweet autumn clematis (paniculata) is evergreen there and grows rampantly. The spring-blooming Armand clematis, also evergreen, likes mild climates.
The slender Texas clematis (texensis) is so amiable that it ranges from South to north; in the coldest places (like Minnesota), it needs hilling up, and the top dies each winter.
If winter hardiness is in question, the following large-flowered varieties are reported as growing successfully in the northern-most states:
- Jackman, Lanuginosa candida
- ‘Duchess of Albany,’ Henryi’
- ‘Nay Moser,’ ‘Elsa Spath’
- “Ramona”
- “Lord Neville”
- King Edward VII’
- `Mme. Edouard Andre
- “Mme. BaronVeillard”
- C omte ss e de Bouchard’
- Lawsoniana
- ‘Duchess of Edinburgh’
- ‘Mrs. Robert Bryden’
The tangutica obtusiuscula, paniculata, and crisp are also seen there, and probably many other large-flowered kinds not included in this list will do just as well.
Planting Practices
Milling up to 12” inches in fall is regularly practiced in these areas to protect the plants against extreme cold, freezing and thawing, and rodent damage. Therefore, spring planting is only recommended there, but fall planting will also succeed in milder zones.
Specific rules observed in caring for Clematis wherever they grow will make them bloom and grow better. The first is to arrange to keep the roots cool while allowing the top plenty of sun.
Usually, this means giving the plant an east or west exposure (not south) or putting it to the north of something low enough (like a garden wall) to allow full sunlight.
If planted in the open on a trellis or fence, the coolness can be provided by a ground cover plant at the base or a thick mulch.
The remaining care comes after planting. Practice mulching instead of close cultivating. Water if the soil becomes dry.
Feed annually with rotted manure or equivalent fertilizer, and occasionally add limestone if necessary. Winter mulching or ’tilling should be done depending on the severity of your winters.
Pruning
Pruning is simpler than it has been made to seem. You won’t prune the first year or two unless cold has killed the top and left dead stems to remove.
After the vine gets big and husky, cut it back in early spring to about 2′ feet, and thin out weak canes.
Most varieties profit by pruning, but a few bloom on old wood and should not be pruned heavily before blooming: ‘Belle of Woking,’ `Drich ess of Edinburgh,’
Montana Rubens, Montana Superba, Montana undulatea. On the other hand, no clematis require pruning, and if you choose to skip the whole operation, they will go on blooming. The flowers may be small, and the plants so tidy, as if you pruned them.
Common Clematis Problem
Probably the thing that gives the large-flowered Clematis their reputation of being “difficult” is that sometimes one will curl up and die for no apparent reason. Sometimes it fails one stem at a time; other times, the whole plant may collapse almost instantly.
This is not an everyday happening. Many gardeners never experience it, but it makes a lasting impression when it does occur. The cause is a disease. It may be one of several kinds, but they all act much alike and have similar results.
In the South, part of the trouble in growing large-flowered Clematis is caused by nematodes in the soil, which cause root knots. As a result, plants are stunted and unthrifty.
The remedy for this is to plant only disease-free plants in soil fumigated at least two weeks earlier with one of the soil fumigants, such as methyl bromide or chloropicrin.
Ask a garden supply dealer about these, and follow the package’s directions, for they are dangerous poisons.
41218 by Rachel Snyder