Tower of Jewels is an unusual biennial plant in the borage family (Boraginaceae) native to the Canary Islands, where it grows on rocky, volcanic hillsides in cool dry summers. It will tolerate temperatures down to 25 F. It can reach heights of 8 feet in bloom and requires full sun in medium moisture to dry light, well-drained soils. It does best in arid conditions. It will reseed itself within its hardiness zones. The first year it produces a 2-3 foot wide basal rosette of silvery green, long thin leaves. The second or possibly the third year a 5-7 foot tall flower stem emerges with the same narrow silvery leaves as the rosette. In spring, this is topped by hundreds of dark rose-pink flowers with protruding stamens in a dense terminal spike. Flowers bloom in late spring to early summer in their native habitat. They then set seed and the plant dies. Even in death, it is attractive. It received the Royal Horticultural Society’s Award of Garden Merit in 2002. This is a plant for tropical gardens in zones 9-10. However, with a greenhouse and a very large pot, it could be grown further north. Insects, Diseases, and Other Plant Problems: No significant problems.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.