There are so many specialty plant groups of which we are particularly proud but no other gives us the pleasure we get from our remarkable collection of clematis. The large flowered Jackman type have always been popular and the choices available today provide a wide range of color. These varieties flower only on new growth and are pruned back heavily in Spring. Perhaps more desirable are those types that flower on old wood early in Summer and again later on new growth.
Some of these varieties are Bees Jubilee (mauve-pink), Duchess of Edinburgh (double white), Lasurstern (large deep blue), and Vyvyan Pennell (double violet blue). A unique feature of the double flowered varieties is that the double flowers appear only on the old wood and single or fewer petalled on the new growth. Knowing the flowering habits of your Clematis is important so that you know how to prune.
Dig a hole 45 cm x 45 cm (18″ x 18″). Place 2 shovels of composted manure at the bottom of the hole. Soil mix for planting should be topsoil (no peat moss), 2 handfuls of blood and bonemeal and 1 handful of horticultural lime, mix well.
Clematis are planted with the crown 8-10 cm (3-4″) below the soil surface. This enables the plant to recover should it be damaged or infected with clematis wilt and so they may reshoot from those buried nodes.
Clematis need a cool and moist root environment, cool best being achieved with a mulch. Keep well watered during hot summers.
Therefore, remember the 4 main aspects on planting clematis:
- Plant in full sun (most varieties).
- Plant the crown 8-10 cm (3-4″) deep.
- Mulch the root zone for a cool environment.
- Keep Clematis moist.
Clematis do not self-cling but climb by curling their leaf stems around a support. They climb readily on a chain-link fence. On a wall, wires should be every 25 cm in a grid and held off from the wall by one inch or more.
- Hard: These varieties flower on new growth only. Therefore they require hard pruning every spring. Cut back to pair of buds near base in March or April. Plant in a sunny location.
- Half: These varieties flower on new growth only. Therefore they require pruning every spring. Prune back to half the height in spring to obtain blooms on new wood. Plant in a sunny location.
- Optional: Prune to shape only after bloom time. These varieties will grow in any aspect – north, south, east or west.
- Light: Prune to shape only. These varieties will grow in any aspect – north, south, east or west.
- No: These varieties produce magnificent huge blooms with eight or more sepals in early spring on previous year’s ripened wood. They often will reflower on new wood in early fall. Do not prune these varieties. They will grow in any aspect – north, south, east or west.