Salvia verticillata aka Lilac Sage

Salvia verticillata is a perennial in the mint family, Lamiaceae. Its common names include lilac sage and whorled blue sage. Its native range runs from central Europe to central Asia and Iran. It grows in temperate regions and is not native to Britain or Ireland. Gardeners grow it for its summer flowers and upright form.

The plant forms a bushy clump and loses its leaves seasonally. RHS gives a height of 1.6–3.3 feet [0.5–1 metre]. Its spread is 0.3–1.6 feet [0.1–0.5 metres]. Chicago Botanic Garden describes a compact plant reaching 2 feet [0.6 metres]. Plants take two to five years to reach full size. The dark green leaves have a coarse texture. Sources describe their shape as either arrow-like or lyre-shaped. The foliage also has a scent.

Small flowers grow on many slender spikes above the leaves. Their shades range from violet-blue to purple and red-purple. Bloom starts in early summer and can last into autumn. Chicago lists flowering from July through October. Cut off spent flower spikes to help extend the display. Butterflies visit the flowers, adding wildlife interest to beds. The spikes provide a clear upright shape among other border plants.

Choose full sun and soil that drains well. Shelter the plant from cold winds that dry its growth. Suitable soils include chalk, loam and sand. It accepts acid, neutral and alkaline conditions. Chicago lists moderate watering, while Missouri notes tolerance of drought and dry soil. It also tolerates shallow, rocky ground and resists deer. RHS rates it H5; Chicago lists USDA zones 5–8. Use it in borders, rock gardens, gravel beds or cottage gardens. It also suits containers, courtyards and wildlife gardens. Raise plants from spring seed or divide them in spring. Stem cuttings offer another way to grow more plants.

Care needs are low, though pests and diseases can occur. Slugs, snails, aphids, capsid bugs and leafhoppers may attack it. Rosemary beetles can harm young shoots. Whitefly and scale sometimes occur too. Watch for leaf spot, rust and powdery mildew. Other possible diseases include verticillium wilt and root or foot rot. Honey fungus is a rare risk. Missouri reports no serious insect or disease problems overall. The supplied sources give no guidance on food use or toxicity.