Persicaria microcephala 'Red Dragon' open ground or trough Morning or afternoon sun is

Morning or afternoon sun is best

native to Central Asia  (Kyrgyzstan

A spreading clump suitable for drifts

more spread

I've never had them as quite densely as in this photo though

Persicaria microcephala 'Red Dragon' open ground or trough Morning or afternoon sun isSpikes of tiny, deep dragon pink to red flowers above striking foliage. Chinese Knot weed, grown for its foliage rather than flowers which are small and white. Each leaf is sharply pointed, with maroon and green patterning and a pale white margin. It quickly develops into a handsome, upright clump. Sun or part shade. Easy going. 60cm forms a stong clump. By By Acabashi wikimedia commons