Howells' Gardeners' Classification of Clematis


These groups are in the approximate order of flowering.

1. The Evergreen group

2. The Alpina group

3. The Macropetala group

4. The Montana group

5. The Rockery group

6. The Early Large-Flowered group

7. The Late Large-Flowered group

8. The Herbaceous group

9. The Viticella group

10. The Texensis group

11. The Orientalis group

12. The Late Mixed group

e.g. C. armandii

e.g. C. alpina 'Frances Rivis'

e.g. C. macropetala 'Markham's Pink'

e.g. C. montana 'Mayleen'

e.g. C. x cartmanii 'Joe'

e.g. 'Nelly Moser'

e.g. 'Jackmanii'

e.g. C. integrifolia 'Rosea'

e.g. 'Madame Julia Correvon'

e.g. 'Gravetye Beauty'

e.g. 'Bill Mackenzie'

e.g. C. flammula


Group I
The first of the clematis to bloom are those of the Evergreen group. They flower from early winter onward. Examples would be C. cirrhosa and C. armandii, both making very large plants. They surprise everyone in winter with unexpected profuse flowering.
Group II
Then comes the hardy Alpina group. They make a selection of single multi-coloured bells from early spring on plants of medium height. Examples are 'Frances Rivis' and 'Jacqueline du Pré'
Group III
Almost at once blooms the Macropetala group. Here we have not single but double nodding bells in a variety of colours from early spring onwards on plants of medium height. Examples are 'Markham's Pink' and 'Jan Lindmark'.
Group IV
Now comes the dramatic entrance of the Montana group. Indeed many, not aware of the beauties that have gone before, regard these as starting the clematis season. A plant can be huge, almost overpowering, and covered with thousands of blooms. Examples are 'Freda' and 'Mayleen'.
Group V
While the above have been catching attention, below them at almost ground level is the lovely Rockery group. Hardly exploited yet, this in time will be a popular section for the beauty of the delicate flowers. Examples are C. marmoraria and C. x cartmanii 'Joe'. They flower from early spring onwards.
Group VI
The Early Large-Flowered bloom on growth made the previous year; so naturally they need little pruning or the blooms will be pruned away. They bloom from mid-spring onwards. Examples are 'Dr Ruppel', 'General Sikorski', 'Miss Bateman', 'Nelly Moser'. This is the group vulnerable to 'wilt'.
Group VII
The Late-Large Flowered bloom on growth made in the present season; so it makes sense to prune them severely in the early spring so as to encourage them to produce strong growth to make an abundance of flowers later. They bloom from early summer onwards. Examples are 'Comtesse de Bouchaud', 'Gipsy Queen', 'Hagley Hybrid', 'Jackmanii'.
Group VIII
The Herbaceous group contains a number of wonderful plants for borders which clamber over other plants rather than climb. Being herbaceous they lose their stems in the winter. Examples are C. 'Durandii' and C. integrifolia 'Rosea'. They can flower from early summer onwards.
Group IX
The Viticella group is of outstanding merit and outclasses the Large Flowered group for garden worthiness. These clematis tend to send out very strong stems, sometimes to a great height, and are covered with a large number of medium-sized flowers from early summer onwards. They are trouble free, hardy, and have fascinating shapes and colours. Examples are 'Madame Julia Correvon' and 'Little Nell'.
Group X
The Texensis group of late summer again has distinctive qualities making bushes of medium height which tend to climb or clamber over other plants. The flowers are tulip or trumpet shapes of glowing colours. Each flower is of such beauty as to demand individual attention. Examples would be 'Gravetye Beauty' and 'Sir Trevor Lawrence.'
Group XI
The Orientalis group contains the truly yellow clematis. The yellows are vivid. Fine seedheads are a feature of this group. Bushes are usually of medium height but some can be tall. They flower mid-summer onwards but are more conspicuous in early autumn as colour disappears elsewhere in the garden. Examples are C. 'Bill Mackenzie' and C. tangutica.
Group XII
The Late mixed group brings the clematis year to an end in a burst of glory. Some of the plants are very vigorous as well as being scented and flower to late autumn. Examples are Clematis flammula and Clematis potanini.

Reference: Howells. J. 1992. A Gardener's Classification of Clematis. The Clematis. p34.

For more clematis information by John Howells click the highlighted titles below.

John Howells' Work on Stem Rot (Clematis Wilt)

Pruning the Twelve Groups of Clematis

Round the Year Care of Clematis

Five Ways of Combining Roses and Clematis

Twelve Easy Combinations of Roses and Clematis

Exploding Myths About Clematis

Pronouncing Clematis

Clematis for North Facing Walls

A Brief History of Clematis


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