Clematis alpina Blue Dancer, with these larger than average, very attractive blue flowers, giving us a second flush of flowers this week (the main show is in April/May).
A foray into the back issue of The Telegraph now, for an article written by Val Bourne, which, whilst it does not mention Blue Dancer at all (a more recent introduction, this article dates from 2003), does cover both Clematis alpina and the related macropetalas.
The photography is mine, so the contents of this post aren’t wholly – what is the word? – lifted/robbed/pinched/swiped/diverted/bagged/shanghaied/pillaged? – from my betters!
High climber with shady roots
These early and small-flowering clematis make terribly useful garden plants, says Val Bourne
Sometime during late April or early May, before my garden is truly awake, the ragged flowers of clematis appear. Their names, ‘White Moth’, ‘Columbine’ and ‘Purple Spider’, suggest their urchin form – as different as it is possible to be from the flat dinner-plate clematis of summer proper.
They belong to the Atragene group of clematis and the easiest to grow are bred from two species: C. alpina and C. macropetala. Both produce an abundance of flowers – usually against fresh leaf – and the ragged appearance is formed by petal-like sterile stamens (staminodes) enclosed by tepals.
Macropetalas tend to look fuller and more double than alpinas as the staminodes are as long as the outer tepals. They also tend to come in stronger colours and often flower repeatedly throughout the summer. The alpinas have shorter staminodes and often look like single flowers with a neat central boss. Many come in blues and rose pinks and these are more vigorous than the white varieties which can be difficult to grow.
How to get the best from your clematis
The Atragene group make two demands on the gardener. First, it is most important that they are given as good drainage as they get in their natural habitat. C. alpina is found in mountainous regions across Europe, while C. macropetala grows in similar situations across northern China, eastern Siberia and eastern Mongolia. Putting coarse grit into a large planting hole is the best way to avoid waterlogging during winter.
As with all clematis, roots should be shielded from the midday sun. They can be shaded by a low wall, a trellis, a container or a ground-cover plant. A nine inch square slab of stone or paving can be placed above the root ball and hidden under soil. This will keep the roots cool and moist in summer.
When planting small- flowered species and their cultivars, place them level with the soil and choose a position where the young growth will be sheltered.
Where to grow
Once given good drainage the Atragene group are useful garden plants. They can thrive in cold, windy situations and make ideal plants for north and east walls. If happy, they will grow to eight or 10 feet in height.
Their small, irregular flowers blend well with delicate cottage garden plants – hardy geraniums, dicentras and violas. They can be trained through roses and shrubs or planted to tumble over walls, surround a gate or spill from a container and, after flowering, many produce silky seedheads. They are gentle plants and do not smother their supporters.
The Atragene group flower on the previous season’s wood and must not be cut back to the ground during spring. Thin or gently restrain the shoots straight after flowering if needed.
A useful rule of thumb when pruning clematis is to remember that if the clematis flowers before June it only needs a light trim after flowering. If it flowers after June, then it needs to be cut back to the ground ( above a shooting bud) in February or March. Be watchful though. If the weather is very cold – bide your time.
There are three different pruning regimes used for clematis and every plant sold has full instructions printed on the label.
The best to try
Forms of Clematis alpina:
‘Columbine’ Raised by Ernest Markham ( the head gardener of William Robinson) at Gravetye Manor in 1937. Light green foliage and nodding, very neat, pale blue bells with greenish white centres.
‘Constance’ AGM Introduced by Raymond Evison in 1992. Deep pink, semi-double irregularly shaped flowers and serrated leaves.
‘Frances Rivis’ AGM The original English form was a seedling grown by Cedric Morris at Benton End in the 1960s. It was found in Frances Rivis’s garden in nearby Saxmunden in Suffolk. There are now two forms – one Dutch and one English. Both have bright, deep blue bells with creamy white centres. The English form has twisted petals and the Dutch has straight petals.
‘Frankie’ AGM Introduced by Raymond Evison in 1990. A vibrant blue, more open flower with brighter white inners and very free flowering.
‘Jacqueline du Pre’ AGM Introduced by Barry Fretwell in 1985. The small pink bells remain half shut and the back of each bright-pink petal is lined with a silvery pink on the outer edge.
‘Pink Flamingo’ AGM Introduced by Raymond Evison in the 1990s. Very pale pink semi-double flowers with darker veining on the outer tepals – a delicate flower.
‘White Moth’ Introduced by George Jackman in the 1950s. A compact climber reaching six feet. Small, white, semi-double flowers with a creamy white centre which are borne on upright stems away from the foliage.
‘White Columbine’ AGM Raised by Treasures of Tenbury in 1987. Uniform nodding white flowers with a greenish white centre.
‘Willy’ Raised in The Netherlands in 1971. Large, single, rose pink flowers with an open shape revealing a neat centre. The backs of the tepals have a deep pink blotch by the stem.
Forms of Clematis macropetala:
‘Lagoon’ AGM Raised by George Jackman in 1958. A semi-double flower enclosed by four slender deep blue petals surrounding creamy white stamens.
‘Jan Lindmark’ Raised in Sweden and introduced by Raymond Evison in the 1990s. Rosy-purple, spidery flowers with lots of long petals producing a full downward- facing flower.
‘Maidwell Hall’ Raised by Oliver Wyatt at Maidwell Hall in Northamptonshire in 1956. French navy ragged flowers very full of petals, surrounding bluish stamens.
‘White Wings’ Raised in Sweden in 1970. Four narrow petals open widely to reveal greenish stamens.
‘Purple Spider’ Raised in The Netherlands in 1992. Very dark-purple flowers full of long petals followed by large seedheads.
‘Wesselton’ Raised by Jim Fisk at Wesselton in Suffolk in the mid-1990s. Very slender, twisted mid blue flowers, packed with petals, and a nodding downward-facing habit.
‘Markham’s Pink’ AGM Raised by Ernest Markham (head gardener at William Robinson’s Gravetye Manor) in 1935. Deep pink flowers of four large tepals surrounding lots of smaller ragged petals, forming a very full semi-double flower.
Where to buy
Thorncroft Clematis Nursery The Lings, Reymerston, Norwich, Norfolk NR9 4QG (01953 850407; www.thorncroft.co.uk). Send 5 x 2nd class stamps for a catalogue. Mail order and delivery all year round
The Paddocks Nursery, Sutton, Tenbury Wells, Worcs WR15 8RJ (01584 819558). Send 2 x 1st class stamps; mail order available.
Longstock Park Nursery, Longstock, Stockbridge Hampshire SO20 6EH; mail order; send £2 cheque for catalogue; (01264 810894; www.longstocknursery.co.uk).