Most clematis enjoy being exposed to at least 5 to 6 hours of sunlight daily. In hotter inland and canyon areas, planting pastel pink varieties in bright shade helps to minimize fading.
THE PLANTING SITE
This is a critical step to insuring the longevity of your clematis. In heavy or adobe soil dig a big hole, preferably 24"x 24". In lighter or sandy soil, a hole 18"x18" will do the trick. Save only the best of your topsoil. Amend the soil as conditions dictate.
Always cut the container before planting your clematis. This minimizes the risk of damaging your plant when removing it from the container. Gently remove the clematis rootball from the container and plant it in the hole so that the base of the plant's stems are sunk 3" to 5" below soil level. Leave the original stake on the clematis for the first year to act as a support as well as a protection against accidental breakage.
Place a 3" to 4" layer of soil amendment or peat moss over the root zone. Keep the mulch 8" away from the stem to avoid stem rot.
Clematis are heavy feeders. In spring, once the clematis buds are about 2 inches long, start feeding them with Gro-Power Flower 'n' Bloom. Alternate feedings every 4 to 6 weeks with Gro-Power All Purpose Plus. Use approximately 2 tablespoons per plant. Continue this alternate feeding until the end of September.
Clematis need regular watering. Always water thoroughly and deeply during the hot summer months. Don't keep them too wet, especially in the winter when they're dormant.
Clematis need support to grow. This can be achieved in many ways. From growing them on an arbor to up a trellis, onto other shrubs, on a fence, or an obelisk, the possibilities are only limited by your imagination.
PLANTING IN A CONTAINER
Just as in growing clematis in the ground, the following steps for planting in a container are crucial. Select a container that is at least 18"x 18". Fill your container with potting mix leaving an adequate amount of space for a good watering basin. As stated previously, cut the container to remove the plant. Gently lift the clematis's rootball from the nursery container and plant it so that the stems are sunk 3" to 5" below soil level. Feed and water as if it were planted in the ground.
STEM ROT (aka WILT)
Clematis are susceptible to many fungi that can cause them to 'wilt' or turn black and these fungi enter the plant via the stem and work their way up. Although this is a very disappointing malady it is usually not fatal if you planted correctly. Carefully cut off all of the diseased parts of the vine and then disinfect your clippers with Physan 20. Dispose of all these diseased parts in a sealed plastic bag.