There are 297 species of clematis. Some species are shrubby, and some others are perennials. Clematis are found throughout the temperate regions of both hemispheres, and also in mountains in the tropics. The cool temperate species are deciduous, but many of the warmer climate species are evergreen.
The best material for transplanting clematis is one year old shoots, taken in mid April and early May. Clematis will root better if the cuttings are taken at this time. These are less likely to have been damaged by insects than older plants, and are more compact and so easier to move around.
By starting in April, a growing season of six months will produce stronger, more mature plants by autumn and the number of winter casualties will be reduced. Cuttings consist of one node, a leaf, and about 2 inches of internode below. All cuts must be cleanly executed with a sharp knife or razor blade, and immediately immersed in water. Ragged cuts will encourage fungal disease.
Cut the main stem as near as possible just above the leaf joint and cut away the leaves and stalk from one side of the stem and trim off any excess leaves from the other side so that only two leaves remain. This trimming process will reduce loss of water through the leaves of the cutting.
Growing from Seeds
Clematis seeds may take up to three years to produce a flower, but get some germination within a year. Collect ripe seeds in the fall and plant in sterile seed starting mix, covering seeds with a thin layer of sand. Place the container into a zip lock polyethylene bag and place it outside in a shady spot (or a refrigerator) for several months during the winter so that they go through several freeze/thaw cycles.
Then place the covered container in a warm location out of direct sunlight and wait for first seedlings. As the seeds germinate, the small plants should be pricked out of the germinating container and planted into a small pot using a sterile soil-less mix.
The root will be a single long root in the beginning. As it grows larger it will need a larger pot, fertilizer and constant moisture. When the plant has three sets of leaves, pinch out the growing tip to promote branching.
When growing, clematis need to be supported against a wall or trellis. The top of the plant should be about six inches below ground level. This will encourage new shoots to grow from the base of the plant. Clematis planted 18 inches away from a wall will allow
moisture to reach the roots.
Taking Care of Clematis
Train new clematis shoots to the support to prevent the plants getting tangled and spread their growth evenly, and water young plants if conditions become dry in their first year. During autumn, many seed heads will be ripe enough to harvest and sow.