Jerusalem sage, named Phlomis fruticosa in Latin and sometimes called yellow clary or great sage, is a perennial herb native to the Mediterranean region, where it grows from Portugal and Spain to Greece and Turkey. It is also widely available as a garden plant in many countries. Jerusalem sage is shrub-like in appearance and grows 4-6 feet (1.2-1.8 m) tall with upright, hairy stems that turn woody at the base as the plant ages. It has rough, aromatic leaves that are 2-4 inches (5-10 cm) long, dull-green on top and covered in dense, fine, silvery hair beneath.
The most striking feature of Jerusalem sage is its bright yellow, tubular, hooded flowers that grow in large whorls on short spikes. Emerging in late spring to mid-summer, these flowers attract butterflies, bees and birds. It should be noted that the plant's English name is misleading. Firstly, Jerusalem sage belongs to the Lamiaceae family of plants, meaning it is a type of mint rather than a sage. Secondly, it does not appear to have any real connection to Jerusalem, but might have been so named because it is common in the eastern parts of the Mediterranean.
Jerusalem sage is often grown as an ornamental plant and is favored by gardeners for its showy flowers and silvery foliage, as well as for being relatively easy to grow. It is drought- and heat-tolerant, not prone to pests or diseases and is resistant to both deer and rabbits. The plant can be grown in almost any kind of soil as long as it is well-drained and not over-watered. Like many plants native to the Mediterranean, Jerusalem sage prefers full sun to light shade and does not tolerate cold very well, though it can survive temperatures as low as 20 degrees Fahrenheit (-6 degrees C), especially if its roots are covered with leaves or mulch. It can be grown in borders or containers, and can be used as an accent plant or for its cut flowers.
Jerusalem sage is commonly propagated by dividing the plant in late fall or early spring. Tip cuttings taken in the fall can be used for the same purpose, and it can also be grown from seeds. New specimens should be planted 2-3 feet (60-90 cm) apart to allow for the spread of the full-grown plants. Established plants can be heavily pruned back in springtime to keep them looking their best, and to prevent them from developing hollow centers.