Large-flowered hybrids are the best known representatives of the species clematis, valued for their magnificent, large flowers (considerably larger than 10 cm in diameter) and for their long flowering period. There are hundreds of cultivars, but they are more or less susceptible to diseases, and need care. They will green a facade up to 3 metres high. Varieties that flower even when they are still very low are particularly suitable for potting on the balcony. Available varieties and prices can be found in the overview.
These clematis do not like hot southeast or west facing walls, and need a partially shaded location. Many cultivars, like Dr. Ruppel and Nelly Moser, need full shade. The location must be wind protected and the stem base shaded. The soil should be fresh and well-drained -- standing water should be avoided at all costs! The planting distance is between 0.5 and 1.5 metres. When planting, position the roots 10 cm below the surface. If potting your clematis, choose a pot size of at least 12 litres. For available varieties / prices, see the overview.
These hybrid clematis are hardy, frost-resistant, perennial leaf-stem (petiole) climbers, with weak to medium growth. Foliage May - October, not very dense. Growth height 2 - 4 metres. Blooms in May / June. If the flowers are consistently cut off and the soil is fertilised, you'll be treated to a second flush of flowers in August / September. Hybrids come in many colours and petals are sometimes 'double.' The fluffy seed heads are quite beautiful in autumn, but the faded leaves don't tend to fall off by themselves and will need to be cut. Pruning as for group 2: cut all stems to half length at the end of the year.
Large-flowered clematis hybrids are susceptible to mildew and clematis wilt. The risk of powerdery milder is reduced by choosing high qualiy plants (the healthiest cultivars) and planting in an optimal spot with right soil conditions. Proper watering is crucial: the leaves should not get wet (just as with tomatoes). As to the dreaded clematis wilt: varieties that flower early and more than once a ear are more vulnerable than the late summer bloomers that bloom once but continuously (so, the 'summer bloomers,' like Ernest Markham).
A close-meshed arrangement with grid spaces of 20 - 30 cm is optimal. Vertical axes should dominate to create standing rectangles rather that squares. See the table of suitable cable systems at the bottom of this page. Our wire rope trellis design 5050 with steel rods is a good choice-- in the easy or light version or with a medium version for optimal development of the plant. Heavy / massive versions are further away from the wall and can be chosen if the risk of mildew is high.