Salvia guaranitica 'Blue Enigma'. One of my top ten perennial plants. Erect, freely branching up-right habit. Bright dark green foliage. Large lipped bright deep blue flowers on spike like inflorescences.
Grows to 4-5ft in the garden. Must plant in 3's. Plant in a sunny or shady border. Reliably hardy in our border for 9 years.