Knotweed 'Superba'

Persicaria affinis 'Superba' is a vigorous, mat-forming perennial that serves as an excellent groundcover for the front of a border or along a path. It is particularly valued for its long-lasting flower spikes that undergo a beautiful colour transformation. The upright pokers start as a pale blush pink, deepen to a rich rose, and finally mature to a dark crimson-brown. This creates a multi-coloured effect as new flowers continue to appear over several months. The narrow, leathery leaves are evergreen in mild winters and turn a beautiful bronze-red in autumn. This plant is tough, hardy, and adapts well to most soil types, though it prefers a moist but well-drained position. In the UK, it is a reliable choice for suppressing weeds and providing a carpet of colour. While it is vigorous, it is not as invasive as some of its relatives and can be easily managed by lifting and dividing clumps in spring or autumn.

Sun: Full sun to partial shade.

Soil: Any well-drained soil.

Hardiness: H6 — down to −20°C.

Flowering: Jul, Aug, Sep, Oct.