Turkish sage (Phlomis russeliana), also known as Jerusalem sage, is quite insensitive to drought. It is therefore ideal for steppe and gravel gardens.
The perennial is also otherwise robust, easy to care for, long-lived, and adapts easily to many garden sites. You can easily recognize it by the characteristic shape of its whorled flowers.
Origin and Distribution
Popular in many gardens, Turkish sage or Phlomis russeliana after its discoverer, Scottish naturalist Dr. Alexander Russell, is one of at least 100 different species of Phlomis.
A member of the labiates (Lamiaceae), the species-rich genus includes herbaceous perennials, shrubs, and subshrubs. The native range of most species extends from southeastern Europe across the entire Central Asian continent to China.
Turkish sage originates from the mountainous forest regions of northern Anatolia.
Here it is found wild in both coniferous and deciduous forests as well as on the bare ground, preferably in association with hazel bushes. The sun-loving perennial grows particularly well along woody edges, in open areas and prefers dry or rocky substrates.
Turkish sage adapts to many garden environments. It looks great along woody edges, on slopes, in rock gardens as well as in prairie beds.
A dry substrate, as well as root competition, do not bother the robust plant, which is why it is very versatile.
Because of its distinctive growth habit and its height of growth between 35 and 60 inches (90-150 cm), it is best to plant the vigorous perennial in the center of the bed.
There it will fit in excellently with perennials such as mullein (Verbascum), Russian sage (Salvia yangii), cranesbill (Geranium), woodland sage (Salvia nemorosa), germander (Teucrium), lavender (Lavandula), or various ornamental grasses.
The bright golden-yellow flowering Turkish sage harmonizes especially well with blue or purple flowering species.
Appearance and Growth
The densely caespitose growing perennial is very vigorous. It conquers larger garden areas within a short time, which is why it is well suited as a ground cover or gap filler, for example on slopes.
Numerous runners grow from the underground rhizomes, which should be kept in check with root barriers or similar if possible.
The plant is densely leafy, especially in the lower part up to a height of about 30 centimeters. The felty, hairy, heart-shaped foliage is clinging to the stem throughout the winter and drying out by spring.
The perennial sprouts from the rhizome each year, making it easy to overwinter.
Flowers, Flowering Time and Fruits
The vibrant golden-yellow flowers of Turkish sage open between June and July. The typical labiate flowers stand together in several tiers in decorative false whorls, some even branching.
The flower stalks can reach a growing height of up to 35 inches (90 cm). Like all Phlomis, Turkish sage is a popular bee pasture.
The triangular nut fruits that develop after flowering are ovoid, slightly hairy on the surface, and contain numerous seeds.
To prevent uncontrolled seeding of the plants, you should remove faded stems. Turkish sage reproduces very successfully not only by root runners but also by self-seeding.
Turkish sage is not toxic to humans or animals. You don’t have to take any precautions when growing this plant.
Location and Soil
It is best to plant Turkish sage in a full sun location, as this is where it blooms most beautifully.
However, the perennial also feels comfortable in a light semi-shaded spot, as long as the soil is well-drained, rather dry, and rich in nutrients. A loose subsoil is also the best guarantee that the extensive growing root system will find enough space.
Planting Turkish Sage Correctly
In principle, you can plant Phlomis throughout the growing season, provided that the weather permits and there is no threat of frost any more.
However, it is advisable to plant in the spring, preferably from mid to late May, because the plants often need some time before the final growth.
For this reason, you should expect flowering only after one to two years, but for this the long-lived perennial shows its lush splendor the next decades all the more joyfully.
Per 10 sqft you should count on about four to six plants. Plant them at a distance of about 20 inches from each other. Enrich the soil with mature compost and water the perennials well after planting.
You can also use root barriers to limit the proliferation typical of the species. But a natural border of competitive plant species, such as ornamental grasses or cranesbill, also serves this purpose.
Watering Turkish Sage
Additional watering is only necessary during hot summer months. Otherwise the pretty, felty leaves will quickly become unsightly.
Always water from below, never from above, and especially not too abundantly. Turkish sage, which is accustomed to drought, is quite frugal. It cannot cope with excessively moist soil and especially waterlogging.
It can survive occasional dry periods without any problems.
Proper Fertilization of Turkish Sage
When it comes to fertilizing, the frugal flowering wonder doesn’t cause you much work either: provide it with some mature compost in the spring after cutting, then it will have enough nutrients for its lush growth.
Cut Turkish Sage Correctly
Because the gray-green leaves remain on the stem well into the fall and often even into the winter months, creating a decorative element in the autumn garden, you don’t need to cut the plants back until spring.
Cap the above-ground parts of the plant that are now withered just above the ground and then apply mature compost. Usually, the perennial will sprout again very quickly afterward.
Propagating Turkish Sage
You don’t need to worry about propagating the Turkish sage: The very vigorous perennial does that so reliably itself that you should instead take rather limiting measures.
If you want a carpet-like spread in your garden, simply allow the bee-pollinated inflorescences to mature. The Turkish sage will subsequently self-seed.
Alternatively, simply collect the nut fruits and sow fine seeds directly in the desired new location. Pre-growing on a windowsill or similar is not necessary.
Dividing Turkish Sage
Turkish sage can also be propagated very well by division, although you should carry out this measure for the first time after about ten to 15 years.
Freshly planted Turkish sage needs two to three years to become established in its new location. So once planted, you should not move it again so quickly.
Only if the perennial feels comfortable in the new location and therefore spreads too quickly, you can simply cut off particularly cheeky root runners from the parent plant with a spade and replant them in a new location.
When dividing older plants, it is best to proceed as follows:
- Carefully expose the root ball.
- Using a sharp spade, carefully pry off one or more sections.
- Do not crush the roots in the process!
- Dig up the root parts and replant them separately in a new location.
Since Turkish sage overwinters easily in the garden, you don’t need to take special winter protection measures.
However, you should leave the above-ground plant parts standing during the cold season and only cut them back in the spring, as this serves as winter protection.
In very wet winters, you should also protect the rhizomes from moisture. Otherwise, mold can spread. You can accomplish this by spreading fir or spruce brushwood on the ground, for example.
The brushwood does a good job of keeping the soil dry. But you should remove it in spring just before budbreak.
Diseases and Pests
Turkish sage are also pleasantly uncomplicated with regard to diseases and pests.
The only problem is excessive moisture, which promotes the colonization of fungi. That’s why mildew often spreads in humid summers.
You can easily recognize it by yellowish to brownish spots on the tops of leaves and a grayish-white fungal turf on the undersides.
Cut away infested foliage and spray the diseased plants with a homemade horsetail broth. Afterward, the leaves should be allowed to dry quickly, and the site must also be kept dry.
Typical garden pests, such as the otherwise voracious slugs, on the other hand, usually leave the Turkish sage alone.
Species and Varieties
In addition to the Turkish sage, you can find the following three species in many gardens.
All species bloom between June and July, and their distinctive flower whorls can be yellow, pink, or red. In terms of their site, soil and care needs, each species is very similar.
The pink-flowering Phlomis tuberosa needs a full-sun, warm location and gets along very well with other sun-loving perennials, such as common sage (Salvia officinalis) or lavender (Lavandula).
Phlomis tuberose spreads through root systems that grow underground. However, it grows rather slowly and densely caespitose.
Greek Jerusalem Sage (Phlomis Samia)
Greek Jerusalem sage blooms a pretty brownish to pinkish-purple and forms dense rosettes of leaves, which is why this species is often used as a groundcover. Like Turkish sage, the species grows to about 90 inches tall.
Jerusalem Sage (Phlomis Fruticosa)
Native to the Mediterranean region, this bright yellow flowering species grow shrubby and reaches heights of up to 3.5 inches.
Since the evergreen species are not frost-hardy, it often freezes back severely in cold winters. However, it reliably resprouts from the rootstock in spring, so overwintering is usually unproblematic.
Phlomis fructicosa is suitable for the design of Mediterranean or steppe gardens.