Strobilanthes attenuata Blue Carpet

Strobilanthes attenuata Blue Carpet is relatively unknown to gardeners but is nevertheless a pretty,perennial,hardy and easy to grow groundcover. It is comfortable even in impoverished soil under shrubs and forms herbaceous clumps that are quite tall, adorned with dense spikes of beautiful blue-violet tubular flowers from late summer until frost. These flowers bloom above abundant oval, hairy, strongly veined leaves which colour beautifully in autumn. This deciduous Himalayan plant can adapt to the sun in cool climates, but generally prefers partial shade or shade.

Strobilanthes attenuata is one of the few hardy species in this genus, which includes over 250 species, mostly native to Madagascar or tropical-temperate Asia. It belongs to the same family as acanthus, the Acanthaceae. The 'Blue Carpet' cultivar differs mainly in the colour of its flowers. The plant forms a woody-based clump of upright stems, reaching 80 cm (32in) to 1.20 m (4ft) in all directions, depending on growing conditions. The stems are characterized by swollen nodes and bear opposite, oval, toothed, matte green leaves. The bright blue-violet flowers are composed of 5 unequal lobes and have a curious flared and bent tube shape, grouped in tight inflorescences at the top of the branches. The foliage turns purplish-pink in autumn before disappearing in winter. This plant spreads in width through lateral stems that produce roots, spontaneously layering.

Strobilanthes are still relatively unknown, despite being a remarkable and useful perennial and hardy species for shaded areas. Strobilanthes 'Blue Carpet' will thrive on the edge of a woodland or under a hedge, even in soil filled with roots. It can be grown here with small periwinkles, dead nettles, or even Waldsteinia ternata. Further north, this plant will tolerate a sunny exposure, for example in a rockery with dwarf asters or tall sedums. In warmer regions, it is better to plant it in a shaded border with ferns, Japanese anemones, or Actaea simplex. In partial shade, its large blue spikes will complement the golden plumes of Solidago rugosa or the rays of Ratibida pinnata.