As climbers, Clematis are unsurpassed in their long flowering presence, their rich diversity of flower shapes, their wide array of colors and tolerances in terms of exposure and climate. It is no wonder they are so popular! From tree huggers to container varieties, there is a Clematis for every garden and flowers for almost every month of the year!
Members of the Ranunculaceae family, Clematis include more than 300 species, hundreds of hybrids and are divided into ten main groups, each with consistent flower size, blooming season, pruning and garden use characteristics.
The Early Large-Flowered clematis group derives mostly from three Asian species: Clematis patens, Clematis florida and Clematis lanuginosa.
- Their flowers are incredibly large, 6-10 in. across (15-25 cm). Star-shaped, they may be single, semi-double or double and are available in a wide range of colors.
- These clematis can reach up to 6-10 ft. (2-3 m).
- They usually bloom in two waves. They bloom in late spring or early summer on the previous year's growth. They often repeat blooming in late summer and early fall on new wood.
- These clematis are usually full sun or partial shade tolerant. Ideally, Clematis prefer having their 'heads in the sun and their feet in the shade'. Keep the roots cool and shaded by other plants or add a layer of pebbles or flat stones at the base. Afternoon shade is appreciated in hot summer areas.
- These clematis are quite versatile. They can be trained over trellises, arbors, pergolas, arches or fences. They can grow through shrubs, climbing roses and into small trees. They can be grown in large containers too.
- The foliage of these clematis is prone to clematis wilt.
- These clematis belong to the second group of Clematis: they should be pruned in late winter or early spring before new growth starts and after the first flush of flowers in early summer.
- Prune in late winter or early spring: Remove dead or weak stems before growth begins. Check individual stems from the top down until you reach a pair of healthy buds, and prune just above them, removing the spindly or damaged growth above. Avoid heavy pruning or flowers will be lost
- Then prune again after the first flush of flowers: To encourage a second flush of flowers later in the season prune back some stems by cutting to large buds or a strong side shoot immediately below the blooms. Top-heavy or overgrown plants can be gradually reduced over two to three seasons by pruning back harder after the first flush of flowers. They are unlikely to produce a second flush of flowers, but should flower again the following year, in late spring or early summer
- Alternatively, leave clematis in this group unpruned, and then hard prune them to 30-90cm (1–3ft) from the base every three or four years in late winter (as for pruning group three). In the first year after renovation, they will only flower once.