Echium pininana
Pride of Tenerife, Tower of Jewels
Grows 10 to 18 feet tall! In the Boraginaceae family. Hardy in zones 8 to 10. Flowers packed tightly along the tall spike. A biennial or short lived perennial, seeds are available from Thomson Morgan. Available as a 4 inch Specialty Annual at the nursery. Right now they are just scratchy little things, but magnificence is promised.
The BBC Gardening’ Plant Finder description of this plant starts out (I love British people,): “Anybody who has been on holiday to the Canary Islands will have probably noticed…”
Other crazy huge things: Leonotis, Digitalis ferruginea.

