Clematis pitcheri

Clematis pitcheri is a wild species from North America and belongs to the Viorna Group, the so-called leather flowers. It is widespread across the central and southern USA, where it grows in woods and shrubberies on dry to moist limestone soils; it was formally described in 1838 by Torrey and Gray in their Flora of North America. The 2–3 cm nodding flowers are pitcher- to bell-shaped and leathery in texture, with four ribbed sepals whose tips curve back. They appear in violet; in the wild the colour ranges, depending on origin, from red and claret through purple to reddish-tinged green, usually with a darker inside. Fruits with relatively large seeds follow.

From June to September the flowers open on the current year's growth. At 200 to 250 cm in height, Clematis pitcheri climbs up a trellis, frame or obelisk; because it is herbaceous and dies back above ground in winter, it stays easy to manage in smaller gardens and in containers. It thrives in sunny to partially shaded positions in well-drained, preferably alkaline soil. Do not plant too deeply – the crown should sit just below the soil surface. As the species is prone to mildew, an airy position suits it well.

Clematis pitcheri is quite hardy (zone 6, down to about -23 °C). Cut it back to about 25 cm in March – this spring pruning ensures vigorous regrowth and abundant flowering. A mulch of compost in spring and autumn feeds the plant and protects the root area.