Strange Smell Doesn’t Detract

This article was first published on 02 Dec 2016.

Some of the early flowering perennials are spring stunners but can be upstaged by other growth popping up for summer.  At Dunedin Botanic Garden, though, pretty spring perennials are still enticing visitors to the herbaceous borders just inside the main gates.

An unusual one bursting into flower is Crambe cordifolia.   A very bold and robust perennial, it has large, bold, crinkled, dark green leaves.  In late spring a profusion of small, fragrant, white flowers, attractive to bees, appear on tall, multi-branched spikes, looking similar to gypsophila.  

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 1.5 metres.  It forms substantial clumps of a similar width.   

Crambe requires shelter from strong winds as the large flower stems can break off, if exposed.  It prefers a well-drained soil; in fact, is drought-tolerant, due to being deeply rooted, and can cope with full sun.  Somewhat sensitive to movement, 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.