Rosmarinus officinalis "Tuscan Blue"

'Tuscan Blue' is the robust, broad-leaved aristocrat of the upright rosemaries, a fast, strongly vertical form grown as much for the deep blue flowers as for the kitchen. Thicker in leaf and richer in bloom than the common rosemary, the cultivar is the same Mediterranean herb, Rosmarinus officinalis, now moved by botanists into the genus Salvia as Salvia rosmarinus, though few cooks will trouble to relearn the name.

Rosemary takes its name from the Latin ros marinus, the dew of the sea, for the plant clothes the dry coastal hills of the Mediterranean in a blue haze within reach of the salt spray. The herb has kept close company with people for more than two thousand years, burned as a purifying incense, carried in wedding and funeral wreaths as the emblem of remembrance, and steeped as a tonic tea thought to quicken a flagging memory. In the kitchen gardens of Tuscany, from which this selection takes a fitting name, the tall, resinous branches season the roasting lamb and the wood-fired loaf.

In the garden, 'Tuscan Blue' makes a bold, architectural evergreen four to six feet tall, useful as the sunny backbone of an herb bed, a fast informal screen, a specimen in a large pot, or a heat-and-drought-proof anchor in a Mediterranean or gravel planting. The deep blue to violet flowers, carried in profusion from winter into spring, are richer in color than most rosemaries and hum with early bees. Set the plant against silver lavender, gray santolina, and bearded iris on lean, sharply drained ground, and give room for the strong upright frame to rise.

Vigorous and quick to fill in, 'Tuscan Blue' wants full sun, sharp drainage, and a faintly alkaline soil, and holds evergreen through the mild winters of USDA zones 7b to 10, roughly to the middle teens Fahrenheit where the roots stay dry. Site the shrub beside a path, a doorway, or a seat, so the resinous scent rises at every passing, and keep a pot on hand at the cold edge of the range to carry a plant under cover through the hardest freezes. Handsome, fragrant, generous in bloom, and useful in the pot and the pan alike.