Plant Profile: Perovskia

Native to arid areas of Central Asia, Perovskia is a woody perennial or sub-shrub to 100-120cm, now recognised as a subgenus of Salvia, though still mostly marketed under its original name. Just two of the ±8 species are grown commercially—toothleaved P. atriplicifolia (syn. Salvia yangii), and dissected-leaved P. abrotanoides—but there are a number of useful cultivars apparently of hybrid origin.

Perovskia’s value in urban situations derives from its rapid growth, long flowering, and low demands in a variety of soil types. Upright stems of grey-green foliage support dense sprays of intense lavender- to violet-blue flowers on distinctive velvety white stems from July well into autumn. Always a striking sight in flower, when lit by low sun, Perovskia takes on a hazy, luminescent effect that can be unforgettable.

A position in full sun minimises its tendency to flop open (the species’ only real defect). In recent years, a number of cultivars have been introduced that are dwarfed and neater in habit (e.g. the 60cm ‘Little Spire’), though these, too, still tend to fall open if not propped. However, the self-supporting American varieties ‘Rocketman’ and the denser ‘Prime Time’ (both bred by Walters Gardens) have been selected for stiffer stems and a tighter habit. Drought-tolerant and tough, Perovskia is not fussy about soil type: like other sub-shrubby Caucasian sages, it thrives in poor soils but tolerates even heavy clay as long as there is no waterlogging. Given appropriate drainage, frost hardiness is excellent. Plants are best cut back hard once growth recommences in spring. This late pruning minimises the risk of rot in the tender new shoots, which then grow rapidly to produce good foliage volume by mid-season (useful for an informal seasonal hedge).

Sun-loving Perovskia dislikes being crowded but combines well with fine-textured grasses such as Stipa and Sporobolus in mixed plantings.

By Martin Deasy, a tutor on the RHS Mhort. He also runs his own landscape design business.

This article was first published in the November 2023 edition of FloraCulture International.