'Blue Spire' is a selection of perovskia that grows about 3 to 4 feet tall and 2 to 3 feet wide (though it will grow larger if over-watered). New wood is white and fuzzy; leaves are a soft green to grey-green and finely cut, giving it an airy appearance. Flower spires of fuzzy, lavender blue flowers begin in June and continue through the summer months. Useful in the perennial or shrub border, with ornamental grasses, and as a cut flower.
Grow in full sun and well drained soil. Tolerates a wide range of soils including loamy-clays, poor soils, and sandy soils. Tolerates a lot of heat, including reflective heat. Over-watering will cause the plant to grow larger than is typical, to be a bit floppy, and to spread, sometimes with reckless abandon. Cut back hard in late winter to early spring (see Guides).