Named for the 17th century Russian general V. A. Perovsky, Russian sage (Perovskia x hybrida) makes an impact in nearly any landscape. This woody-stemmed sub-shrub grows up to 5 feet high and 4 feet wide. A haze of tiny blue or violet flowers covers the entire crown of the shrub for three months or more throughout spring and summer, and the long-lasting flowers attract honeybees. Russian sages are equipped to handle dry climates and adapt to rainier zones as long as the soil does not remain wet or boggy. They grow in USDA hardiness zones 3 to 9. Although not a true sage, they are related to sages (Salvia sp.) and have similar silver-green foliage.
Similar in appearance to the original Russian sage (Perovskia atriplicifolia), 'Blue Mist' is aptly named. Instead of lavender, a cloud of pale blue flowers halos the shrub. 'Blue Mist' also has an earlier bloom time, with flowers appearing in early spring rather than late spring. Size and care is identical to other Russian sage varieties, requiring sun and well-drained soil.
'Blue Spire' leaves are more deeply cut than the leaves of 'Blue Mist.' The flowers are a deep violet, and the bloom time is close to the original Russian sage. 'Blue Spire' grows to 3 feet tall, and leaves lower on the sub-shrub are heavily cut while the smaller leaves higher up the stems are toothy. It is just as drought-resistant as its progenitors.
'Filagran' has the most heavily cut leaves of any Russian sage variety. “Perennials for Every Purpose” describes the leaves as the “most beautiful filigreed leaves of the group.” 'Filagran' has light blue flowers, suggestive of 'Blue Mist.' 'Longin' is another Russian sage cultivar, but 'Filagran' and 'Longin' are nearly identical. Some growers consider these two cultivars to be the same hybridized sage, sold under two different names.