A group of very large plants with giant inflorescence of blue flowers.
Plant Type
All Plants, Biennials
Hardiness Zone
9-10
Sunlight
full
Moisture
average, low water requirements
Soil & Site
well drained
Temperature
tolerates occasional temperatures down to 25 degrees F, may die from successive low temperatures
Flowers
sky blue to rose colored in a scorpiod cyme (cyme with flowers or branches alternating in opposite ranks)
Leaves
rosette silver-green lanceolate leaves
Dimensions
8-10 plus feet tall in warmer climates
Propagation
two years from seed to produce a flowering plant, reported to be easy to germinate
Native Site
Native to the Canary Islands.
Author's Notes
It would be a bit of a challenge to grow "The Tower of Jewel" true to form in hardiness zone #5. Being a biennial it would take two years and it is a large plant. May well be worth the effort to add a very exotic element to the garden. They were impressive plants at the Chicago Botanic Garden.
Notes & Reference
#51-Armitage's Manual of Annuals, Biennials, and Half-Hardy Perennials (Alan Arimitage)
,#109-Annuals and Tender Perennials for North American Gardens (Wayne Winterrowd)