Phlomis — Jerusalem Sage
While many California natives and Mediterranean flora are drought tolerant during our long dry season, a preponderance of these is not summer-blooming, a goal sought after by most gardeners. The fuzzy-leafed Mediterranean native Phlomis species are indeed both drought-tolerant as well as summer-blooming with enough other values to be taken seriously as key garden features.
These low-water, shrubby perennials hail from the Mediterranean to Eastern Asia and China. They bear slightly fuzzy, bluish green leaves heart-shaped at the base and sunny yellow flowers arranged in whorls, candelabra-style, with several flower clusters up and down vertical stalks.
Although none of the many species are considered garden anchors—not imposing enough to be considered year-round features—they do carry evergreen foliage, interesting forms, and seasonal blooms that partner easily with many other species. A phlomis in bloom is a dramatic sight with its unusual and arresting arrangement of flowers and the contrast between the yellow blooms and the blue-green foliage. Flowers attract the attention of bees and butterflies, making it a good habitat plant. Deer avoid it completely.
Phlomis fruticosa reaches about 3-4 ft. high and wide, although some individual specimens grow larger. Planted on 3-4 ft. centers, they create an impressive mass planting. Shrubs come into bloom at the end of April and beginning of May in Sonoma County and will rebloom one or more times if watered moderately and cut back lightly as flowers fade. After the final bloom of the season, cut back by half to maintain an attractive form.
Phlomis endures high heat in summer, prefers full sun for best bloom, and may get leggy and droopy in too much shade. Flower stalks and seed heads continue to be ornamental and provide food for birds as they dry and turn brown in late summer.
A groundcover form, Phlomis russeliana, features bold, heart-shaped, green leaves that cover spreading stems. Tall flower stalks to 3 ft. in height provide a striking contrast against the lower, spreading foliage. In early summer, stalks carry several vertical ranks of clustered yellow flowers that turn rich brown when dry and may be left standing for many weeks. This species endures considerable shade where it requires very little summer water. Because the current season’s leaves and stems slowly die back after bloom, plants stay neater with one or two foliage clean-ups as new growth emerges.
A cross between P. fruticosa and P. russeliana, Phlomis ‘Edward Bowles,’ is perhaps the most dramatic of the genus as it spreads up to twice the width of its 3-ft. height and flowers similarly to its parents. Long horizontal stems become woody after a few years and can be cut back drastically to maintain a compact shape.
Phlomis combines well with ornamental grasses and other Mediterranean-climate species, especially those with blue flowers.