Nodding bells of early clematis
Spring flowering clematis bring a particular charm to the garden with their dainty nodding heads and lush foliage
Dark, pointed buds, birdlike in appearance, emerge from the branches of a clematis, alongside its newly developing green, serrated leaves. While the stems lengthen and grow upwards, the slowly fattening buds remain down-pointed on elegant curves. Eventually, four sepals part to expose white petticoats. By the time the leaves have covered the plants, there will be a cascade of colour which lasts for many weeks. Proving big is not always best, spring flowering clematis, in the Atragene Group of plants, have small flowers compared to their more well-known and blowsy relatives, but their charm and ease of growth makes them a firm favourite with those who have come to know and love them. Although the flowers lack fragrance, their delicacy and colour are a delight in spring. A colour range based on white, pink, plum, mauve and blue brings a torrent of beautiful, nodding flowers from April through May, depending on the variety, the season and the position. They have delicate, fern-like foliage, early flowers and attractive fluffy seedheads in late summer, sometimes with the bonus of a few late blooms.
These are adaptable plants that shrug off frosts and cold winds, flourish in sun or part-shade and are some of the few flowering climbers which will thrive in an east-facing position. They do not need regular pruning, and they are unaffected by the dreaded clematis wilt, the scourge of the large-flowered varieties.
Unusual flowers
Atragenes belong to the species Clematis alpina and C. macropetala. The former comes from Northern Europe and Northern Asia, with an outlier in the European Alps, while the latter is from China and Siberia. The structure of their flowers distinguishes them from other species. The colourful parts of a clematis flower are not strictly petals, but sepals. In other plants, these green, leaf-like structures, which protect the flower in bud, either drop off or serve no purpose once the flower is open. However, in clematis, it is the sepals which form the main floral attraction. But while most clematis do not have true petals, the Atragenes have petals in the centre of the blooms. In C. alpina, these are usually white, broad and blunt-tipped, to form a cylinder in the centre of the flower around the female parts and the stamens. They are usually referred to as staminodes, being something between a stamen and petal. In C. macropetala, the abundant petals are narrow and pointed. The species name of macropetala means big petals, which might appear strange when they seem to be so small compared to those of other clematis, but it is fitting when one considers that most clematis have no petals at all. The flowers have four, colourful hairy sepals arranged in a bell shape, but the sepals flare more in C. macropetala to create a more showy and starry flower. The sepals are approximately 1½in (4cm) long in C. alpina and up to 2in (5cm) in C. macropetala, the centres being filled with narrow petals that can be almost white towards the middle. There are many cultivated forms available, which may have semi-double flowers or improved flower size, and all are worthy of a place in the garden. The flowers are produced in the leaf axils along the previous year’s growth. The foliage is usually mid green, and each leaf is divided into nine leaflets, in three clusters of three, in both species. The leaflets are coarsely toothed and attractive throughout summer before falling in autumn.
Climbing support
Like all clematis, the Atragenes climb by means of their leaf stalks, which twist around a support, then coil to bring themselves closer for security. The stems themselves do not twine. Because of this, any supporting structure needs to have a small diameter, and with so many leaves grabbing for support, netting is often recommended. As flexible nylon netting itself has to be supported, it is worth investing in something more substantial. Wire trellis is good, and large-profile chicken wire is perfect.
While this might seem a little unsightly at first, the plant will have grown to cover it after approximately a year. This is a climber which is not well suited to horizontal training wires: it needs a broad network of support where it will make a dense wall of growth that is particularly useful for screening. In an established garden, spring flowering clematis can be trained up and through large shrubs. They are not so vigorous that they are likely to swamp other plants, though care should be taken not to allow them to smother conifers, which will be damaged if deprived of light. In the wild, they scramble over small shrubs and rocks in open landscapes. They can be used as ground cover mixed with heathers and shrubs such as alpine willows or spiraeas, planted through a native hedge or allowed to tumble over retaining walls.
Care and maintenance
A vigorously growing plant should gain at least 24in (60cm) per year. If pruned, it may extend considerably more quickly. Atragenes are usually feted as not needing to be pruned, but, even if they are not trimmed for many years, a tidy-up will eventually be required. Without pruning, the new growth will get higher each year, with more dead and dense growth in the centre. Flowers are produced in April, on growth from the previous year, so along with most spring flowering plants, pruning should take place immediately afterwards, around May. This allows the plant all summer to make new growth on which to flower the following spring. If the plant needs to be kept at less than its ultimate height, perhaps because it is in a pot or on a patio, annual pruning will be necessary and will not harm it. All these clematis are hardy and will withstand the coldest winters, and even windy situations. They are among the few climbers which will withstand coastal winds, although they obviously require secure supports. They are not choosy about soil and will grow in acid, neutral or alkaline conditions, but must have good drainage. If planted in wet, clay soils, they are unlikely to thrive, and in such conditions they are best planted in a raised bed or grown in pots. As these plants are potentially long-lived, it pays to prepare the soil well, forking in well-rotted manure or compost and some grit if the soil is on the heavy side.