Clematis thrive beautifully in containers on patios and balconies , climbing up pergolas, obelisks and trellises and adding height and structure to the garden. Garden catalog descriptions of clematis that bloom all summer often seem too good to be true. Some gardeners have trouble getting their clematis to bloom at all because they don’t realize that different groups of clematis require different pruning measures. However, horticultural experts confirm that some clematis varieties can actually bloom throughout the summer. Be careful when selecting clematis for your garden, care for them properly, and you will enjoy the blooms of these beautiful climbers until early fall.
Table of Contents
- Clematis viticella are low-maintenance perennial bloomers
- Clematis x Jackmanii impresses with exceptionally large flowers
- Clematis Durandii is ideal for container growing
- Clematis Texensis
- Clematis ‘Warszawska Nike
- Clematis florida ‘Alba Plena
- Clematis ‘Rouge Cardinal
- Care tips to keep your clematis blooming all summer long
- The clematis pruning groups explained
Many of the summer-flowering clematis are in pruning group 3, which blooms on new wood, the shoots formed after radical pruning in the spring. Read on, because in the article we still explain when and how to prune clematis. Most summer-flowering clematis are hardy to zone 6.
Clematis viticella are low maintenance perennial bloomers.
Cultivars in the clematis viticella group are characterized by an especially long blooming season, from June to September, and are known for having few site requirements. ‘Madame Julia Correvon’ produces its red flowers throughout the summer. Long-flowering varieties still include the lilac-pink to reddish-flowered ‘Ernest Markham’, the blue ‘Lady Betty Balfour’ and the red ‘Ville de Lyon’.
‘Lady Betty Balfour
‘Ville de Lyon’
Clematis viticella ‘Night Veil’
A particularly popular viticella cultivar is ‘Night Veil’. From June to September, it enchants with its enchanting flowers in dark purple. It grows up to 250 cm tall, is frost hardy and is perfect for pergolas, fences or obelisks .
Clematis viticella ‘Etoile Violet’
The velvety flowers of ‘Etoile Violette’ appear a lovely blue-violet during its long blooming season from June to September. Climbing, it reaches a height of up to 300 cm.
Clematis x Jackmanii impresses with exceptionally large flowers
Clematis x Jackmannii hybrids also bloom throughout the summer on new wood. Particularly long-flowering cultivars in this group include ‘Superba’ (purple), ‘Comtesse de Bouchard’ (pink) and ‘Star of India’ (purple).
‘Star of India’
‘Comtesse de Bouchard’
Clematis Durandii is ideal for container growing
Clematis durandii was created by crossing Clematis integrifolia and Clematis ‘Jackmanii’. Therefore, it also belongs to the third pruning group and blooms on new wood. Unlike most clematis, Durandii has a compact, shrubby habit and reaches a growth height of up to 150 – 200 cm. It is hardy and robust and blooms profusely with beautiful large, violet-blue flowers. Its flowering period begins in early summer and can last until frost.
Perennial Clematis and Groundcover Rose ‘Sea Foam’
Texas woodland vine (Clematis texenis) is another compact clematis variety that boasts an exceptionally long blooming season from June to October. It has scarlet, bell-shaped flowers and dense foliage. Its shoots are more herbaceous than woody and reach a height of 2 to 4 meters. It blooms from summer until frost on new wood. Like other summer bloomers, C. texensis needs a sunny location. Among the most beautiful texenis varieties are ‘Sir Trevor Lawrence’ and ‘Princess Diana’.
Clematis ‘Warszawska Nike’
This clematis charms with its large, purple flowers from early summer to late fall. Its flower center of white stamens is also fascinating, especially pleasing to bees, bumblebees and butterflies.
Clematis florida ‘Alba Plena’
Clematis ‘Alba Plena’ blooms with greenish-white flowers continuously from June to October. Characteristic of the variety is its attractive flower shape, reminiscent of that of dahlias.
Clematis ‘Rouge Cardinal
Clematis ‘Rouge Cardinal’ presents its large crimson flowers already from the end of May. Its main flowering period is from June to September. It is hardy and easy to care for and feels most at home in a sunny to semi-shady spot.
Care tips to keep your clematis blooming all summer long
When buying clematis, choose plants that are at least two years old (in 2-3 gallon pots) so that the roots are well developed before planting.
To encourage flowering and strengthen shoots, fertilize clematis in the spring. Fertilize once a week with tomato fertilizer, which is rich in potassium. If you keep clematis in a container, choose a large container and repot in compost soil every two years. Mulch the surface around the roots to protect the base from the sun.
Summer-flowering clematis need to be cut back annually. If your clematis bloom in early summer, May/June, they are in Group 2. Clematis varieties that bloom from June to September are in Group 3 and need to be pruned back to 30 to 50 inches above the ground.
The clematis pruning groups explained
Pruning group I – light pruning as needed
- Concerns mainly the Clematis alpina and Clematis montana species.
- Shorten only a few shoots to keep the plant in shape or to strengthen its growth and flowering vigor.
- The ideal time is at the end of May, after flowering.
Pruning group II – light pruning
- Especially for varieties that bloom twice a year.
- The optimal time for pruning is in February-March, removing dead, damaged and diseased shoots.
- Cut back to just above the strongest and highest pair of buds.
Pruning group III – heavy pruning that encourages the formation of new shoots with numerous flowers.
- The varieties in this group bloom exclusively on the new shoots.
- Prune the clematis in March, about 30 to 50 cm above the ground, to just above the first pair of buds.