Whether climbing up posts and fences or wandering through shrubs, clematis flowers provide an extravagant show of color. Flowers vary from 1 inch to 5 inches across, and bloom in shades of white, yellow, soft pink, velvet red, and rich purple. Delightful fluffy, feathery seed heads develop on the vines after blooms are gone.
There are three categories of clematis-early-flowering species; early to midseason, large-flowered cultivars; and late, large-flowered cultivars. Each is pruned a little differently. (See below.) There's also great diversity in flower shape-single and double large-flowered, saucer-shaped, star-shaped, bell-shaped, tulip-shaped, and tubular-shaped.
Common name: Virgin's bower, old man's beard, traveler's joy
Botanical name: Clematis spp.
Plant type: Evergreen or deciduous woody or semi-woody climbers
Height: 2 feet to 30 feet, depending on species and cultivar
Zones: 4 to 11, depending on species and cultivar
Family: Ranunculaceae (Buttercup)
- Sun: Foliage and flowers require full sun to part shade, but roots require cool temperatures and shade.
- Soil: Humus-rich, well-drained soil. In sandy soil, add 50 percent peat moss or compost. In clay soil, mix in 50 percent coarse sand or compost. Don't add peat moss to clay soils because it may keep the roots too wet.
- Moisture: Water regularly to maintain even moisture.
- Mulch: Add 2 to 3 inches of organic mulch to help keep roots cool.
- Fertilizing: For maximum bloom production, keep well-fertilized during the growing season.
- Pruning: There are three methods, depending on the type of clematis you have.
- Type one: Flowers bloom on previous year's shoots in spring. Remove dead and weak stems after all flowering is done.
- Type two: Flowers bloom on new side shoots on last year's stems in late spring and early summer and on tips of new growth in late summer. Prune all dead material above the emerging buds in early spring.
- Type three: Flowers bloom in summer and early fall on this year's growth. In February or March prune out dead stems that appear above new leaf buds growing low on the plant. Flowers will bloom later on new growth.
- ‘Parisienne' (pictured) is from the Raymond Evison Patio Clematis Collection, chosen for its ability to do well in containers. It grows just 3 to 4 feet tall and has 4-inch-wide blooms from spring to fall. Zones 4 to 9. (In cold climates, overwinter in a protected site or plant in the garden in fall.)
- ‘Jackmanii' is a late, large-flowered climber with dark purple flowers. Grows 10 feet tall. Zones 4 to 11.
- ‘Mme. Julia Correvon' is a late, small-flowered vine with bell-shaped, single, burgundy flowers. Grows 10 feet tall. Zones 4 to 11.
- ‘Nelly Moser' is an early, large-flowered vine that has pale pink flowers with darker pink bands down the center of the petals. Grows 6 to 10 feet tall. Zones 4 to 11.
- Plant annuals or shallow-rooted perennials around clematis roots to help keep the roots cool and shaded.
- When planting or transplanting, fill the new planting hole with humus-rich soil and a handful each of 5-10-10 lime (if needed) and superphosphate. Plant the crown 1 to 2 inches deeper than the soil level in the container. This will encourage strong shoots from below ground. Fill in soil around the roots and stems, being careful not to break stems.
- Clematis grows and flowers best in neutral soil, so add lime only if you know your soil is acidic. Lime will make it more neutral. When soil is acidic, existing nutrients in the soil will not be available to the plant.
- If you don't know the type of clematis you have, observe the vine over the growing season and note when it blooms and whether it blooms on old (brown and woody) stems or new (green) stems. Then choose from the pruning choices above.
Pests and diseases
- Aphids, scale, and whiteflies occasionally attack plants.
- Clematis wilt causes part of the vine or the entire vine to go from healthy to wilted and black in just a few days. Remove damaged leaves and stems, water the plant, and drench the soil around the plant with a fungicide.
- Clematis stem rot is a fungal disease that starts on stems near the soil line. Red lesions appear near the base of the stem; as they get larger, they girdle the stem, causing the upper part of the plant to wilt and die. Remove and dispose of infected stems.
- Take cuttings in spring.
- Transplant clematis in early spring when soil is workable.
All in the family
- There are about 1,800 species in the Ranunculaceae family, mainly in colder regions. Some well-known garden plants in this family include monkshood, marsh marigold, meadow rue, hellebore, and love-in-a-mist.