Salvia concolor

This photo is from my garden last year. This is a spectacular salvia growing to 10ft., and more here. Native to Mexico, this is an upright-growing salvia, and it is totally hardy in the South of the UK. Dormant in winter, it will resprout in May, and phenomenal growth then takes place. The deep blue flowers with matching calyces are quite small, but the long flowering stems are superb from August until October. A fantastic salvia, easy to grow, though relatively unknown here. Occasionally sets seed here, best to take cuttings. It is inclined to droop in hot conditions, and requires regular deep watering. Semi-shade might be advantageous. It is very prone to red spider-mite in hot, dry weather.