There are at least 297 species of Clematis. These are mostly hardy perennial often woody vining plants most notable for their flowering starting in Spring through Summer with a few notable species producing spectacular displays into the Autumn.
Some species are evergreen or partially so. A few like C. recta of India is a dwarf and shrubby species growing little more than 4ft/1.2m.
They can withstand some considerable cold but are often then killed to the ground by freezing; reappearing in the Spring. And most species also thrive in milder climates into the cooler subtropical regions. There they may eventually become woody climbers that sometimes remain evergreen or partially so. Many of the most spectacular flowering forms are completely deciduous; producing rapidly growing vining stems each Spring from a central rootstock.
Spring-flowering Clematis flower from new shoots produced off of last year’s woody stems. Summer and Autumn flowering Clematis bloom off of new growth shoots produced that season. Multi-flowering Clematis usually flower off of both shoots arising from last year’s older woody growth and also this season new shoots.
Most Clematis species are native to eastern Asia, mostly the Himalayas and China. Several natural hybrids occurred there that were then introduced into Japan in the 17th Century. Many lovely cultivars originated there that eventually reached Europe and the Western World during the 18th Century onward.
Once these lovely Clematis species became established in the gardens of North America they soon became known as the "Queen of Vines". One native North American species, Clematis viorna, is also known as ‘Leather Flower’ or ‘Vase Vine’ in allusion to this flowers shape and texture. Another North American species C. ligusticifolia, became named by Spanish Colonialist and later settlers of America’s ‘wild west’ as ‘Pepper Vine’. Since its seeds and highly acrid (somewhat toxic) leaves were used as a substitute for pepper!
Another very decorative and popular species and the only one native to Europe, C. viticella, is known as ‘Virgins Bower’ This species comes in blue, blue-purple and red with semi-pendulous blooms. This was the first species introduced from Europe to the United Kingdom around 1569. It was first associated with Hugh Morgans’ apothecary gardens for Queen Elizabeth, the ‘Virgin Queen” and thus the inspiration for the common name it carries today.
Clematis vitalba, ‘Old Man’s Bearded’ or ‘Traveller’s Joy’ is the only British/European species to ever earn a disagreeable reputation as a rather invasive species. This is a perennial, quick-growing species native to alkaline and chalky ground often in the bush and forest areas of Wales. Pretty but very simple white flowers 2-2.5cm/1inch across are born mostly in Summer. These appear in small clusters and are more a star-burst of very prominent stamens above small and thin creamy white petals.
These flower clusters are followed by wispy ‘beard’-like plumy seeds in Autumn and Winter which gives the entire vine a distinctive smoky appearance This is a very effective species for arbors and was planted extensively during Colonial days in colder climates where its growth is checked by severe freezing But this fast-growing species has become invasive when introduced into milder climates such as New Zealand and the Northwest Pacific Coast of North America.
The best known New Zealand species is the lovely Bush Clematis, C. paniculata, or Puawhanganga which means "Sacred Flower". These are rather fast-growing and scrambling vines that tend to crown out and become bush over shrubbery, trees and taller supporting structures. They are awe-inspiring when seen completely smothered in radiant cream to soft yellow or pristine white, large star-like flowers up to 10cm across towering through the native forest reaching for a blue Spring sky. Being a variable native species, flower forms can vary from a very simple four-petaled thin cross with small central stamens to a much more substantial bloom with broader broad petals that can often number 6-8 and sometimes fully double in form.
Its Himalayan relative, Clematis montana, in pristine creamy white (C. Montana alba) and Dogwood pink (C. Montana rubra) are more commonly grown in gardens and are very hardy. These are fast-growing vines that remain semi-evergreen in milder climates. The flowers (2-3inch/5-7.5cm across) usually have a soft vanilla fragrance and completely smother the vines in Spring. These flowers are four-petaled in a crucifix shape that closely resemble Cornus florida (American Dogwood) in both colour and season of their flowering making them quite a compatible compliment in moderate temperate climates. Their Autumn foliage often turns an attractive burgundy/russet/ port-wine shade.
Clematis terniflora, the ‘Sweet Autumn Clematis’, is a very robust climber that remains hardy even in cooler temperate climates. It can easily attain a large size of 20-30ft/6-9m producing attractive glossy green foliage that is deciduous over thin but woody vines. Flowers appear in Late Summer and Autumn and usually have a sweet vanilla fragrance that is very attractive to Bees and Birds. While flowers are fairly small and simple, they completely smother the plant for many weeks creating great cascades of fragrant blooms. C. terniflora is possibly the largest and latest of the Clematis clan.
The Asian hybrids are smaller, mostly deciduous and somewhat delicate climbers with massive blooms in glowing shades. Flowers are mostly in shades of blue, burgundy, lavender, mauve, pink, purple, red violet occasionally yellow, white and many multi-toned colour combinations in Anemone-form, double, semi-double and single forms. These usually grow 8-10ft/2.4-3m.or less.
Most of the Gardeners favorite hybrids are crosses between these Asian hybrids. Most of which originated from crosses between C. viticella (Italian Clematis) that produces late-flowering semi-pendulous blooms; earlier large-flowering C patens; and giant, star-shaped C.lanuginosa. This has resulted in mauve pink-giant striped star ‘Nelly Moser’ and spectacular blue-purple C. jackmanii which favours more closely the C. patens species plus hundreds more remarkable cultivars.
When combined, the nearly 300 species and their multitude of hybrid cultivars can be divided into 19 sections and even more subgroups. The best recognized and most widely cultivated of these includes: Evergreen, Alpina, Macropetala, Montana, Rockery, Early-Large-Flowered, Late-Large-Flowered, Herbaceous, Viticella/Pendula, Texensis, Orientalis and Late mixed
All were original native to forest, meadowland or woodland verges. Thus they enjoy a deep, very well drained, woodland soil enriched with well-aged compost, leaf mould and ample lime. When adding fertiliser to the soil, keep this fairly light and use a basic 10-10-10 good quality balanced blend. Avoid over-feeding Clematis. Most Clematis prefers a soil pH of 7.0-7.5. But they will tolerate more acid conditions. While they thrive in a limy soil, avoid over-liming any planting soil. It is best to apply Lime and let it ‘cure’ in the land for sometime before planting.
Being that these are vines that rise up from the woodland floor and scramble over shrubbery and small trees, they mostly prefer having their feet in cool and moist shade with their heads in full sun or at least very strong morning sunlight. Thus they are almost always best planted on the shady side of an arbor or trellis or in the shade of shrubs, trees and low walls. This helps provide the cool, moist, shaded root run they demand
When planting Clematis dig deeply and create the proper woodland soil in which they thrive. Make the planting hole 18in/40.5cm deep and equally as wide. Clematis are best planted with the root ball 5cm/2inches or more below ground level so that the first two sets of buds shooting off the main growing stem are fully submerged below ground. This allows the plants a cool and moist root run and also the opportunity to create further roots up the stem. This will produce further new rooted shoots encouraging many more blooms.
Clematis are climbing and scrambling vines that attach themselves and cling to whatever support they can find by twisting leaf petioles. These petioles are quite thin and rather short. So whatever trellis or support is provided for Clematis vines must reflect their climbing nature. Stout wooden trellis will not work as these slats are too broad. The ideal support is thin nylon fishing line. Wire will also work provided the growing site is not too hot in Summer. Wire heats up quickly and can easily scald the attached petioles during the heat of a Summer day.
Another very effective way is to provide a small tepee or cluster of tall, thin sticks which can be placed around the emerging vine. These should lead upward to potentially supportive shrubs, a small tree or host vine where the Clematis can continue to cling and sprawl in the sunshine.
Mulch is usually applied at planting time and topped-up before dry and warm conditions arrive in Late Spring or Early Summer. A 4inch/10cm layer of leaf mould and/or light mushroom compost is ideal. Be sure that all mulch is kept well away from the trunk. If mulch comes up flush against the trunk and it remains overly moist, collar rot or Clematis Wilt many result.. Summer mulch is essential to protect the shallow roots. Avoid Clematis roots being exposed to sunny hot spots and drying winds.
The Winter dormancy period is the best time to plant new vines or shift old ones. But they are notoriously difficult to move once they become established. It is usually easier and much more successful to purchase a new plant than to shift an old one. Plants are sometimes sold bare-root in Winter. But most often they are offered for sale when in flower and new growth in Late Spring to Early Summer.
When transplanting Clematis in flower and active growth make every attempt to not disturb the fragile root system when making the shift from bag or container to the permanent growing site. Thoroughly water-in the newly transplanted Clematis immediately after planting. If the root ball does break apart and the plant begins to wilt, it is often wise to removed flowers and buds; trim back soft new foliage and top growth so that the damaged root system can recover without the added stress of sustaining copious amounts of bloom and foliage.
Clematis are usually pruned back at least a little in Late Autumn with the major pruning in Late Winter or Early Spring just as new buds begin to swell. At that time it is easy to determine how much winter-kill has occurred. This can then be easily eliminated. Wherever Winter freezing occurs, it is common for hybrid Clematis to die to the ground. This is not a problem as new growth will quickly emerge with the return of warm weather. Even when a hard kills an evergreen species to the ground, it will often bounce back from the base with new growth.
Always cut back to healthy and strong growth where there are two buds that can emerge from the dormant stem. Make the cut square across the stem just a little higher than the two strong buds. There is no need for slanted cuts. Usually if in doubt, cut back harder rather than less, as Clematis do best on new-grown wood.
Plants can also be lightly pruned directly after a flush of flowers. This is more to eliminate any damaged, diseased or non-flowering and weak growth. Again cut back to a set of healthy and strong new buds. Unless there are signs of die-back or disease, cut back much less sharply with this mid-season pruning; as it is only done to stimulate new growth and blooms from lateral side shoots more than from the ground. However, should the old growth become diseased or infested, cutting to near ground level will often produce healthy and strong new growth and sometimes extra flowering.
Clematis vines are fairly easy to propagate from cuttings. These can come from layering new-season stems to the soil next to the vine. Simply remove one or two sets of leaves at the leaf nodes where the vining stem will touch the soil. Bury the stem at the node(s) and anchor it in place with stones or pin it down with stout wire. Roots should form in 6-8 weeks. Then the vining stem can be cut away and the new cutting potted on and placed in the nursery to grow-on for at least the end of that growing season.
Hybrid Clematis vines are often grafted on to a hardier species root stock. Ungrafted cuttings can sometimes develop Clematis Wilt. There is no cure for this bacterial/fungal attack. But maintaining ideal growing conditions, especially a cool root run, good air circulation, higher soil pH and strong sunlight in a very well-draining soil offer the best chance of success.
If ever a new or old stem does wilt, simply cut it off and burn it. Then disinfect the cutting tool and attempt to correct whatever environmental factor possibly caused the vine to become stressed and vulnerable to attack. If the growing environment can be improved, often new healthy growth will emerge from the base and the vine will bounce back.
Clematis can also be started from stem cuttings taken when the vine is pruned back in Early/Mid Summer. Select a healthy and strong stem. Make the cut where old brown wood meets new wood or at a node where the wood is ‘half-hard’ i.e. just beginning to change from green to brown. Cuttings should be 4-8inches/10-20cm or less in length. Remove all but the top two leaves. Immerse in hormone gel or powder. Drop, don’t push, each cutting into a dibble hole in seed-raising mix or a peat and propagating sand mix. This should be in a seedling flat or plastic pot. Place this in a bright, humid and warm environment out of chilling drafts or scalding sunlight. A propagation box is ideal for this. Sometimes a cold frame will suit. Or place the pot of cuttings inside a clear or translucent plastic bag, drawing it up and over the cuttings to create a mini-terrarium. Usually these cuttings will strike in 4-6 weeks. Then they can be moved on into individual containers in the sheltered nursery or cool glasshouse for the rest of the growing season. Usually the new plants will be ready to pot-on or transplant out the following Early Spring.
Established Clematis plants are usually fed with compost mulch enriched with dolomite or garden Lime and 10-10-10 fertiliser in Early Spring and often again right after a flush of flowers followed by a light pruning. This often stimulates a new flush of growth and flowering. Late Summer and Autumn flowering species will not need this pruning. But Early and Late Large Flowered hybrids and all multiple or repeat-flowering hybrids and species will reward this care with a later flowering.
Clematis can be successfully grown and flowered in bags and containers. The Large Flowered Hybrids that are smaller vines are usually much more successful than the bigger species Clematis with woody vines. Being woodland natives great care must be taken to create an ideal enriched and evenly moist soil that remains continually cool and damp without exposing their roots to extremes of drought and fluctuating temperatures. If ever their roots dry out and foliage wilts or withers, it often remains permanently damaged and the plant may even collapse. Larger containers, planters and tubs made from non-porous materials like plastic or well-glazed ceramic work best. And these containers are best permanently shaded and sheltered from extremes.
Clematis are a fairly modern introduction into the great Kingdom of Plants. From their rather humble beginnings have emerged some remarkable hybrids. And the fact that many of them first arrived through the care and attention bestowed upon them by Buddhist and Shinto Japanese Priests, combined with their very beautiful, almost surreal and vivid flowers that reach for the heavens does certainly earn them the right to claim their name as beloved ‘Sacred Flowers’
MORE PICTURES click here...
READ MORE... e-Book Clematis - 'Freckles'