In the garden many clematis, particularly the large-flowered cultivars, contribute an exotic presence with their showy flowers. Indoors, away from the competition of other garden vegetation, their appeal is accentuated and the scented species can be appreciated to the full.
In large conservatories, some of the vigorous clematis, such as C. armandii with its huge pointed evergreen leaves, will give foliage interest year round, but this plant will need a space of about 4.5 X 3 m (15 x 10 ft) to be able to develop fully. Its scented early spring flowers are marvelous. C. cirrhosa and its forms, especially C. c. 'Freckles', would not require as much space: 2.4 X 1.5 m (8 x 5 ft) would, with training, be enough for it to develop fully. C. c. 'Freckles' has delightful highly colored bell-shaped flowers during mid- to late autumn under glass protection.
It is to the New Zealand species and their more recent cultivars that we should turn for added interest in early spring and for plants that are not quite so vigorous. C. afoliata has no true foliage other than rush-like stems with only the very occasional tiny leaf to be found. Its 2 cm (3/4 in) long cream-colored flowers are slightly scented. C. australis and C. forsteri both have creamy/green scented flowers, those of C. forsteri being the stronger scented, of lemon verbena. Both are early spring-flowering and have evergreen foliage, that of C. forsteri being very pale green while C. australis is some-what darker. C. paniculata has the largest flowers of all the New Zealand species and with selected forms, like those of C. p. 'Bodnant', the flowers reach 5 cm (2 in) in diameter. The flowers are pure white with pink stamens that contrast well with the dark green leaves. This clematis is also early spring-flowering and can be kept within a similar space to that of C. cirrhosa 'Freckles'.
However, the clematis that is a must for color and performance in early spring is C. X cartmanii 'Joe'. It will flower for a month, producing an abundance of 5 cm (2 in) wide white flowers that show up very well against its dark green, coarse, fern-like foliage. It is non-clinging and reaches about 1-2 m (3 1/4-6 1/2 ft) in height if allowed to grow freely, but can be contained down to 1 m (3 1/4ft). For added interest, C .gentianoides from Tasmania can be used indoors. It is a distinctive and unusual clematis, growing to only 45-50 cm (18-20 in) with coarse narrow leaves and strongly scented white flowers.
The late spring and early summer large-flowered clematis, which include the single, semi-double and double large-flowered clematis can be used most successfully in containers or grown in the soil in a conservatory. As they flower at slightly different times, you can choose cultivars to give you flowers over a long period of time. If the plant and the container in which it is growing are not too large, the plants can be grown outside and brought inside at the point of flowering, to be returned when they have finished.
One of the most rewarding of all clematis to grow in a conservatory is the C. florida group: c. f. 'Plena', C. f. 'Sieboldii' and the new cultivar C. f. Pistachio. All of these clematis will grow well outside but they perform much better under glasshouse or conservatory conditions.
Clematis in pots do not do well in the house. But using clematis as cut flowers can be an appealing challenge for the flower arranger.
The flowers to be cut must be carefully selected; discard any damaged flowers, spent flowers or flowers on a weak stem. Cut in the evening. The flower should not be quite fully open and should be on a strong stem. Having cut the clematis stem, the leaves are then removed so as to prevent loss of water by transpiration from the leaves. The ends of the stems are crushed and dipped in boiling water for a few seconds. They are then immersed in water up to their necks and left overnight. It is said that the flowers benefit from a little sugar in the water, a pinch of fertilizer, and some would say a drop of gin.
In the spring, material will be available from the alpina clematis and macropetala clematis, and the early hybrids such as 'Dr Ruppel', 'Bees Jubilee', 'Nelly Moser' and 'Lasurstern'. Even earlier in the spring, there is double pleasure to be obtained from the blooms of the beautiful C. cirrhosa balearica (C. calycina) and the lovely C. armandii, with its very sweetly-scented blooms. C. armandii and C. cirrhosa produce strands as long as 1 m (3 1/2 ft). In the summer, and again in the autumn, there is a very wide choice of available clematis. Some particularly delightful displays can be created by the herbaceous C. x durandii, with its striking flowers; C. fusca is viewed not so much for its beauty, but as a striking point of discussion; C. recta is worth growing for its 60-90cm (2-3 ft) panicles of small white fragrant flowers; 'Huldine' is noteworthy for its semi-translucent white. flower; and 'Henryi' for its stiff, sturdy stem. Other good large-flowered clematis are 'Barbara Jackman' 'Comtesse de Bouchaud', 'Gipsy Queen', 'Hagley Hybrid', , Jackmanii', 'Kathleen Wheeler', 'Lawsoniana', 'Perle d' Azur', 'The President', 'Victoria', and 'W. E. Gladstone'. Double flowers stand out for their elegance, particularly 'Vyvyan Pennell' and C. viticella 'Purpurea Plena Elegans'.
A number of clematis have very attractive foliage. The unusual green leathery leaves of C. armandii can be effective with other flowers. C. cirrhosa balearica has particularly fine, most delicate foliage.
There are also the considerable merits of clematis seed heads or fluffy heads for flower arranging. These can be used as they are, or they can be dried for winter display. Attractive seed heads can be obtained from C. alpina, C. macropetala, C. orientalis, C. tangutica, C. serratifolia, C. fargesii, C. flammula and C. vitalba.
The flowers can be displayed in a variety of ways. They can be shown on their own, maybe even a single bloom, or they can be displayed in conjunction with other flowers. A particularly pleasing way of displaying clematis flowers is with carefully matched roses. Usually the foliage used is the foliage of other plants. The container should be carefully selected to match and enhance the beauty of that particular bloom. An unusual way of displaying clematis flowers is to cut the stem to a few centimeters (1 in) and allow the flower to rest in a bowl of water; patterns can vary with the selection of the colored clematis.
For each 1 liter of water in the plant holder, a teaspoonful of sugar (as a nutrient) and 1/2 teaspoonful of bleach (to kill bacteria) should be added. The flowers will last five to ten days. Should the clematis show signs of flopping, then 2.5 cm (1 in) should be cut off each stem and they should be put in water up to their necks overnight.
To obtain good strong stems, i.e. a bloom with a long peduncle, special attention has to be given to having healthy plants from which to collect the flowers. Thus every attention must be given to feeding. Particularly with the early-flowering large hybrids, care at pruning is of some importance; the stems should be pruned back to nearer the base than usual, to encourage the plant to put out strong growth.
These may be used green or partially or fully dried and conditioned with glycerine for winter dried flower decorations. The early-flowering C. alpina and C. macropetala types produce numerous very attractive fluffy seed heads, while those of the early large-flowered cultivars, including the double-flowered clematis, are larger and the midseason large-flowered clematis larger still. The later flowering species produce interesting seed heads that are variable in size and form, some of the most noteworthy being C. flammula (small silvery seed heads). C. Fusca var. violacea (outstanding large spiked seed heads); C. Petit Faucon (neat round seed heads); C. potaninii var. fargesii (small silvery seed heads); C. recta and C. r. var. purpurea (abundant clusters of spiky seed-heads); C. serratifolia (neat round seed heads); C. tangutica and its cultivars (masses of fluffy seed heads); C. terniflora (in hot climates producing masses of seed heads some of which have a purple color).
The best clematis seed heads for drying are those that by late summer are at the silky stage but have not gone fluffy. Prepare a mixture of one-third glycerine and two-thirds boiling water, stir it well, and pour it into a jam jar or similar container to a depth of about 5 cm (2 in). Cut the stems and immediately put the bases into the mixture while it is still very hot. Do not pack them tightly. Place the container in a cool dry place out of bright light. The stalks and leaves will turn rich brown (you can remove the leaves if you prefer), while the seed heads become a slightly lighter color and retain their silky texture. Check the level of the mixture in the container on a regular basis; it may require topping up with warm solution to keep the depth at about 5 cm (2 in). The correct time to remove the stems from the mixture is when the color is even, which should take 2-3 weeks, though you should keep a check on them. If the leaves are left on the stems, they become slightly oily to the touch. The dried stems, leaves and seed heads should not be put into water or a damp atmosphere.
