An unusual one bursting into flower is Crambe cordifolia.
A robust perennial, it has large, bold, crinkled, dark green leaves and, in late spring, a profusion of small, fragrant white flowers appear on tall multi-branched spikes.
What makes this plant distinct from the usual inhabitants of herbaceous borders, however, is its smell. Crambe cordifolia belongs to the Brassicaceae family and is related to cabbage so its foliage emits a hint of cabbage that weaves through the flowers’ sweet perfume. Despite this slight affront, Crambe cordifolia is a handy plant for the back of a border, reaching a height of more than 1.5m. It forms substantial clumps of a similar width.
Crambe prefers a well-drained soil; in fact, it is drought-tolerant, due to being deeply rooted, and can cope with full sun. Somewhat sensitive to movement and wind, this plant is best left undisturbed, so choose the right location when planting.
Not easily divided, it can fortunately sometimes self-seed and is suitable for root cuttings in winter. Foliage dies down in late summer, so remove old leaves and cut back, if required, to tidy up. Linda Hellyer is curator of the herbaceous borders at Dunedin Botanic Garden.