Beautiful, showy clematis are not as difficult to grow as you might think. Learning when to prune your clematis and giving a little attention to their few requirements will reward you with a magnificent show of colorful blooms.
A beautiful clematis starts with proper planting. Clematis prefer to have their roots in the shade and their tops in the sun. Keep the roots cool with a well-drained rich soil with added compost, peat moss or composted manure and a good layer of mulch. Planting ground cover or other low growing perennials around the base of your clematis will also help to keep the soil cool and minimize weed growth. Organic amendments will help to retain moisture when added to the soil. Feed monthly with a liquid fertilizer or use a slow release fertilizer which can last for up to six months.
A Note About Bloom Rates
For the first few years, clematis may be slow to grow. Just keep in mind that it is establishing its root system, which is essential to a healthy, vibrant plant. In its first year, your clematis may produce very few flowers or even none at all. By the second year there will be more growth and a few flowers. By the third year you should see substantial growth and many lovely blooms.
For the best chance of success if you are new to gardening with clematis, buy plants in larger containers. While smaller starts will be less expensive to buy, they will take a little more work to establish and can be more delicate and prone to failure. If you purchase a pot of any size and are not planting it in the ground immediately, be sure not to allow the soil in the container to dry out or the plant may be overly stressed and vulnerable.
Keep the climbing habit of clematis in mind when selecting your planting site. Allow your plants to grow up into large shrubs and trees, or on a trellis against a sunny wall. Select varieties with growth that will not exceed your shrub or trellis; a 20-foot vine may overwhelm a smaller shrub or a weak trellis and will look overgrown and out of place.
Clematis are divided into three distinctive groups. Knowing what group your clematis falls under will guide you on when and how to prune.
These pruning suggestions are for established vines that have been in the ground for at least three years. Young vines should all be pruned to 12 inches the second spring and to 18 inches the third spring. This helps to develop more shoots, a fuller vine and a better root system.
- Group 1
This group includes certain species clematis and their cultivars which bloom early in the year. Some of the more familiar representatives of this group include the Montanas, varieties of C. alpina and C. macropetala. All of the Group 1 clematis bloom on growth made the previous year. They can be pruned to keep them within their allotted space or to remove dead and unsightly foliage. If they are pruned late in the season or before they flower, however, the cuts may remove potential flower buds and reduce that year’s flowering. To prevent this, prune Group 1 clematis right after flowering.
- Group 2
These are the large flowered hybrids. They are often divided again into two subgroups – 2a and 2b. All of the clematis in Group 2 bloom on ‘old wood’ (actually on short shoots from old wood) and should not be pruned except for deadwood pruning in early spring after the leaf buds open slightly.
- Group 3
These are the summer-blooming varieties such as the viticellas and Jackmanii types that bloom on new wood and the late bloomers such as Sweet Autumn Clematis (C. terniflora) and orientalis types. Clematis in Group 3 mainly flower on new wood produced in the current year and should be pruned back severely every year in late winter, when they are completely dormant, to about 12-14 inches. Leave at least two pairs of buds on each stem of the plant. Most clematis in this group are very fast growing and will reach their full height before blooming every summer.
Once you know how to properly care for clematis, you will find it to be a welcome addition to your landscape. If you aren’t sure just what your clematis needs to thrive, our expert staff will be glad to help be sure you and your plants have a great relationship!