Neither Russian nor a sage, this clumping perennial combines handsome foliage with colorful summer flowers. Mature plants stand 34 feet tall and wide, with graceful, upright, whitish stems holding finely cut, aromatic, gray-green leaves. Sprays of small, lavender-blue flowers appear continuously from late spring through summer, forming a soft haze above the foliage. 'Blue Spire' has deep violet-blue blossoms; 'Filagran' sports silvery foliage and a distinctive upright form. 'Longin' is more upright than the species, reaching 34 feet tall. 'Lacy Blue' and 'Little Spire' grow only 2 feet tall.
Russian sage can be used in the garden in many ways. Its cool-colored flowers and foliage combine well with reds, oranges, and yellows; its fine-textured foliage is a good foil for plants with coarser leaves, such as coneflower (Echinacea), black-eyed Susans (Rudbeckia), iris, aster, and sedum. Mass plantings are very effective.
Even though it is scarcely bothered by pests (not even deer have much interest in it) and withstands heat, drought, and infertile soils, the plant is difficult for some Southerners to grow. The most common problem is heavy, poorly drained soil. If you have clay, try planting in raised beds and mixing gravel with the soil. Water infrequently, and don't fertilize or crowd plants. Instead of pruning in fall, wait until new growth begins in spring, then cut old stems nearly to the ground.