Are you looking for a low maintenance, showy evergreen shrub for your west coast garden? Jerusalem sage is a must-have plant for Mediterranean gardens that gives a lot and asks very little of the gardener. Read on to learn more about growing and caring for this plant.
What Is A Jerusalem Sage Plant?
Jerusalem sage (scientifically known as Phlomis fruticosa) is a spreading evergreen or perennial shrub with upright stems. These plants from the sage family (Lamiaceae) usually grow to around 3 or 4ft (0.9 or 1.2m) high and to about 5ft (1.5m) wide.
The species is native to the Mediterranean, where it is found in countries including Greece and Italy. In those regions, this plant can be found growing in fairly dry, rocky Mediterranean scrubland.Â
This plant has been given the Award of Garden Merit by the Royal Horticultural Society.
The leaves of the Jerusalem sage are a pale, almost silvery-green color and resemble the leaves of the sage plant. The soft foliage is white below and covered in fine hairs, growing to a maximum of about 5 inches (12.5cm) long.
These are attractive, oppositely arranged leaves with great texture and they tend to curl up somewhat from the midrib, showing a whitish outer edge.
Jerusalem Sage Flowers
This plant produces a multitude of attractive bright yellow flowers, each a little over an inch (2.5cm) long. The flowers are hooded and whorled on the stems and fall out in time leaving behind an interesting ball-shaped structure known as a verticillaster.
These plants bloom most profusely in the early to mid-summer, although flowering can occur from spring up until fall.
Similar Species
Phlomis russeliana is also known as the Turkish sage, Jerusalem sage, or Hardy Jerusalem sage. This plant is similar in appearance but does not grow as large, usually taking a mounded shape and growing to about 3ft (0.9m) tall and 2ft (0.6m) across.
This plant, which originates from Syria and Turkey in southwestern Asia, has greener, arrow-shaped leaves that point downwards. Care for this plant is much the same as for P. fruticosa and these plants can be grown in dry to medium moist well drained soil in full sun.
Grow these plants in USDA hardiness zones 5-9 and they will flower throughout the early summer, until the start of fall, providing winter interest thereafter with their attractive dried flowerheads.Â
Other attractive Phlomis plants which can be grown include the golden-leaved Jerusalem sage, C. chrysophylla, and P. cashmeriana, and P. italica which are lovely small shrubs with lavender to lilac-pink flowers.
How To Grow A Jerusalem Sage
Phlomis fruticosa can be grown quite easily from seed. These seeds will usually germinate within about 3 weeks if sown in late spring. (1)
Another good option for propagating new plants is to take 4 inch (10cm) long ripe or semi-ripe cuttings from active, non-flowering growth. These cuttings will take well, provided they are not kept too wet, and it is suggested to periodically air them for a few minutes at a time. (1)
This plant is moderate to fast-growing and will grow well in a variety of fast-draining soils. Site these plants in full sun to achieve the best growth form and flowering. Jerusalem sage will grow in shadier conditions but is likely to be a thinner, less tidy, and less attractive plant there.
These plants are adapted to a Mediterranean climate. This type of climate has warm dry summers and a winter rainy season, much like the conditions found on the west coast of the United States, making this plant a good choice for coastal Californian and Oregon gardens.
Jerusalem sage will thrive as an evergreen if grown in zones 8-10. From zone 7-6 or lower, these plants may survive as a perennial, resprouting from the rootstock, although at the temperatures of zone 5, the roots may die off if not protected.
Care and Maintenance
Known to be hardy and drought-tolerant, these attractive shrubs will grow well in exposed, hot places with minimal care, just as they do in nature.
Being a compact and fairly tidy shrub, the only pruning that is necessary is to neaten it up slightly and remove dead and out-of-place growth. Young plants will, however, tolerate pretty severe pruning and can be cut right back to about 3 or 4inches (7.5 or 10cm) to stimulate dense new regrowth. (2)
If grown in colder climates, prune out any frost damage when the growing season begins. It is possible to prolong the flowering period of these plants by deadheading spent blossoms and triggering a second round of flowers. Leaving the plant to go to seed is also an attractive option, however.
Take care when working with the hairy leaves of this plant as some people report skin and chest irritation after contact. Jerusalem sage does not require regular fertilizing or watering, although plants will benefit from a good watering every now and then in summer and some additional water in winter.
These plants are known to be highly pest and disease-resistant. The only reference to pest damage seems to be leafhopper infestations.
These ¼ inch (6mm) long insects feed on plant sap by piercing the plants with their sharp mouthparts. Severe infestations can result in damage to leaves, particularly along veins, and even leaf drop. Commercially available leafhopper insecticides or organic options like neem oil can be used to control these pests if necessary. (3)
Uses
Horticultural uses
Jerusalem sage plant makes a good border plant and is also showy enough to be a good accent plant. It really shines in Mediterranean and cottage-style gardens.
Being hardy plants, these will do well at the coast and in drier inland areas. Some of the smaller Phlomis species will make an attractive container plant in a sunny outdoor location.
Human uses
This plant is used by some in the same way as the common sage plant (Salvia officinalis), That is, as a garnish or herb used in meat dishes and stews in particular.
Wildlife uses
These plants are great for attracting bees, butterflies, hummingbirds, and other pollinators to the garden. As an added bonus, they are also known to be deer and rabbit resistant.
FAQs
Should Jerusalem sage be cut back?
Yes, Jerusalem sage (Phlomis fruticosa) benefits from occasional pruning to maintain its shape, control size, and encourage bushier growth. Prune after flowering or in early spring by removing dead or damaged growth.
Does Jerusalem sage spread?
Jerusalem sage tends to form clumps rather than aggressively spreading. It can expand gradually through its rhizomatous roots but is generally well-behaved in the garden.
How long does Jerusalem sage live?
Jerusalem sage is a long-lived perennial, and under favorable growing conditions, it can live for many years, often exceeding a decade.
Why is my Jerusalem sage turning yellow?
Yellowing leaves on Jerusalem sage may be due to several factors, including overwatering, poor soil drainage, or nutrient deficiencies. Assess the plant’s environment and adjust watering and soil conditions accordingly.
What is the benefit of Jerusalem Leaf?
Jerusalem sage is valued in gardens for its drought tolerance, deer resistance, and attractive, aromatic foliage. The leaves are sometimes used in traditional medicine for their potential antimicrobial properties, although any medicinal use should be approached with caution and consultation with a healthcare professional.
Conclusion
Phlomis fruticosa is a great plant for Mediterranean gardens and will do particularly well on the west coast. This showy and hardy evergreen asks very little of the gardener but will reward you with cheerful flowers and interesting foliage.
If you love growing plants with yellow flowers, check these types of yellow flower.
References
References
(1) Toogood, A. Propagation: The Fully Illustrated Plant-By-Plant Manual Of Practical Techniques.
(2) Brickell, C. & Joyce, D. Pruning & Training: What, When & How To Prune.
(3) Utah State University. Leafhoppers On Ornamentals.
https://extension.usu.edu/pests/ipm/notes_orn/list-treeshrubs/leafhoppers-ornamentals
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*image by nahhan/depositphotos
