Centranthus ruber 'Atrococcineus' is a perennial treasured for its massed red flowers and summer-long display. It grows to about 0.9 m and favours a sunny aspect in the garden. Plant in freely draining soils — sandy, loamy or even clay that drains — and give it full sun exposure. Flowers appear from June to September.

Red valerian 'Atrococcineus' (Centranthus ruber) is a fully hardy perennial to 0.9 m that flowers from June to September.

https://en.wikipedia.org/wiki/Valeriana_rubra

Valeriana is a genus of flowering plants in the family Caprifoliaceae, members of which may be commonly known as valerians. It contains many species, including the garden valerian, Valeriana officinalis.

Centranthus ruber 'Atrococcineus'

Red valerian 'Atrococcineus' | Centranthus ruber 'Atrococcineus'

Centranthus ruber 'Coccineus' is a columnar upright perennial in the Caprifoliaceae, notable for an extended summer flowering display. It is semi-evergreen and produces clusters of blooms from June to September. The cultivar prefers a sunny, south- or west-facing position in well-drained soil. It suits exposed coastal sites as well as sheltered garden corners.

Red Valerian Centranthus ruber 'Coccineus' flowers from June to September and prefers full sun on well-drained alkaline or neutral soil.