Clematis patens Rouge Cardinal

Clematis patens 'Rouge Cardinal', commonly known as Clematis Rouge Cardinal, is a striking and vigorous deciduous climber with striking large, velvety crimson-red blooms. A classic hybrid bred in France in the 1960s, it has remained a much-loved choice among gardeners for its reliable performance, late summer flowering period, and dramatic floral display. This variety is part of the large-flowered clematis group and is especially appreciated for its long flowering window and adaptability to a variety of planting situations.

The foliage of Clematis Rouge Cardinal is made up of medium to dark green leaves, arranged in a pinnate pattern. The leaves provide a fresh, verdant backdrop to the vibrant flowers,  the real highlight of this variety. The flowers are single, large, measuring around 12–15cm across, and borne in profusion from mid- to late summer (usually July to September). The flowers are a rich crimson red, with a subtle velvety sheen and slightly ruffled petals, often complemented by contrasting creamy stamens. As the flowers age, they become more purple red. The flower colour is particularly intense and tends not to fade in strong sunlight. 

How Hardy is Clematis patens Rouge Cardinal?
Clematis Rouge Cardinal is fully hardy throughout the UK, capable of withstanding temperatures down to around -20°C. It performs well in most UK climates provided it is planted in well-drained soil in a sunny position with roots kept cool and shaded.

Eventual Height and Width of Clematis patens Rouge Cardinal
When mature, this climber can reach a height of approximately 2.5 to 4 metres, with a spread of about 1 to 1.5 metres. It will climb by twining leaf stalks and is ideal for training up trellises, fences, obelisks, or even through shrubs and small trees.

Uses in Garden and / or Landscape
Rouge Cardinal is perfect for vertical interest in borders, cottage gardens, and mixed beds. It’s especially effective when grown against a pale-coloured wall or structure, where the vivid red blooms can really shine. It also makes a striking companion to climbing roses or lighter-coloured clematis varieties for a dynamic colour contrast.

Care Tips
Clematis Rouge Cardinal prefers a sunny or partially shaded site with moist but well-drained soil. As with most clematis, the roots should be kept cool—planting low-growing plants at the base can help. This variety belongs to Pruning Group 3, meaning it should be cut back hard in late winter or early spring to about 20–30cm above ground level to encourage vigorous new growth and flowering. Regular feeding during the growing season will support strong blooms.