Salvia argentea (Silver Sage)

Salvia argentea, commonly called Silver sage or Silver clary, is a herbaceous short-lived perennial or biennial, forming a compact basal rosette of large silvery woolly leaves. When in bloom, the rosette is topped with a tall panicle of small blush-white flowers arranged in whorls around the stems.

It is a drought-tolerant plant native to the Mediterranean basin, specifically to southern Europe and northern Africa.


Quick Overview

TYPE

Type herbaceous

HEIGHT & WIDTH

Salvia argentea height and width

BLOOM TIME

Salvia argentea bloom time

SUNLIGHT

full sun

HARDINESS

hardiness (-15ºC / 5º F)

DROUGHT TOLERANCE

drought tolerance aprox 4 months

ORIGIN

origin mediterranean basin

Taxonomy

  • Botanical name: Salvia argentea  (SAL-vee-ah ar-jen-TAY-ah
  • Family: Lamiaceae (lay-mee-AY-see-ee)
  • Common name: Silver sage, Silver clary
NameMeaning
SalviaDerives from the Latin word Salva meaning to save or heal. Referring to the healing properties of salvias.
argenteaComes from the Latin word argentum meaning silver. Referring to the silver-white leaves.

How to identify Salvia argentea

Salvia argentea plant (Silver sage)

Plant

Herbaceous plant forming a large basal rosette of broad silvery woolly leaves entirely covered with long silver hairs turning white in summer. A tall panicle of white flowers emerges from the rosette when it blooms in the summer.

The leaves persist during the winter unless the climate is very cold.

After the flowers bloom, the leaves lose their silvery colour and become grey-green. After the summer, when the weather gets cooler, the silver-grey colour returns.

The plant´s foliage has an average height of 20 to 30 cm (0.6 to 1 ft). The panicle is 60 to 80 cm (2 to 2.6 ft) tall. The width is around  60 cm (2ft).

Salvia argentea stem (Silver sage)

Stem

The stems are upright, very branched from the base and covered with short, dense white hairs. They are initially herbaceous but become woody over time.

Salvia argentea leaf (Silver sage)

Leaf

The leaf is large with a green upper surface and whitish green or white lower surface. Both sides are densely covered with long silky hairs, creating a woolly effect.

The shape of the leaf is ovate or ovate-oblong with a rounded tip and cordate base. It is entire, with an irregularly crenate margin and petiolate (has a stalk).

The size varies between 8.5 to 28 cm ( 3.3 to 11 in) long and 6.4 to 20 cm  2.5 to 9.8 in) wide

Salvia argentea flower (Silver sage)

Flower

The inflorescence is a panicle 17 to 70 cm (6.6 to 27 in) tall with several whorls composed of 6 to 10 white flowers tinged with yellow or pink. At the base of the whorls are two opposite green, ovate, acute bracts that remain after the flower falls off.

The corolla is two-lipped, the upper lip has 2 lobes laterally compressed, forming a hood, and the lower lip has 3 lobes with the middle lobe much larger and forming a cupped shape (which acts as a landing platform allowing bees and other insects to enter the flower). The stamens are inserted under the hood of the corolla with the anthers peeking outside, and the long pistil sticks out from the top.

Each flower is held inside a green calyx that is bell-shaped and 2-lipped with five triangular teeth, three on the upper lip and 2 on the lower one.

The flowers bloom in early summer.

Salvia argentea Usage

Ornamental

The Silver Sage is grown for its lovely foliage, which consists of large, whitish woolly leaves forming a wide rosette at the base of the plant. It is a bold plant with year-round interest.

In the summer, emerging from the rosette is a tall flower panicle with whorls of white flowers along the stems.

It can be used as a solitary plant or planted in a group. It can be planted in pots or borders. In rock or gravel gardens.

Due to its soft furry leaves that invite people to touch them, it is an ideal plant for special-purpose gardens for the blind and for children.

This plant is short-lived, but if you leave the flowers, it will self-seed and produce new plants that will continue in the garden for many years 

Medicinal

A study indicates that Salvia argentea may have antioxidant properties which can be used for therapeutic purposes.

Biodiversity

The flowers of Silver sage are a good source of nectar, being very attractive to bees. They enhance the biodiversity of your garden.

Salvia argentea Habitat

Silver Sage grows in the typical Mediterranean landscape at altitudes up to 1700 m (6700 ft).

It is seen in dry grasslands, rocky slopes and roadsides, in free-draining soil.

How to care for Salvia argentea

Cold exposure

This plant is hardy, tolerating temperatures down to -15ºC (5ºF) or colder as long as the soil is well drained. It does not support cold and humid soil.

Add some mulch to protect the crown from excess moisture. The preferred mulch is gravel to protect the leaves from rotting. Other types of mulch hold too much humidity.

Sun exposure

It needs full sun (at least 6 hours per day) to maintain prettier foliage and to flower more abundantly. However, it can tolerate some shade.

Soil

It likes hot, well-drained to dry, stony or sandy soils. It especially dislikes wet soil, which makes it more exposed to fungal diseases. 

If prefers poor soils, if they’re too fertile, it has more difficulty tolerating drought and cold temperatures.

It grows well in most types of soils: mildly acidic, neutral and mildly alkaline.

Watering

Silver sage is drought tolerant and can go for some time without water (about 4 months if the temperature is not too hot). 

Overwatering will probably kill it. In particular, the combination of heat and humidity can lead to fungal disease.

To preserve the soil´s moisture, you should add mulch around the root area of the plant. Gravel is the best option for mulching this plant.

How to prune Salvia argentea

Cut off the diseased or yellow leaves to maintain the vigorous growth and healthy appearance of the foliage.

Silver sage is a short-lived perennial, but you can extend its life by cutting the flower stalks as close to the base as possible before the flowers produce seeds.

On the other hand, if you want the plant to self-seed and grow new plants each year, don´t prune back the flower stalks.

How to propagate Salvia argentea

Sage can be propagated in different ways:

  • Silver sage can be easily propagated from seed, and it will actually self-seed if you don’t cut back the flower stems.
  • It can also be propagated by division. In the second year of its life, the silver sage usually produces off-shoots. Gently dig up these baby plants and re-plant them

A good online source for plant propagation techniques can be found at RHS.

If you prefer books, I can recommend the following:

  • Creative propagation: a grower’s guide by Thompson, Peter,
  • RHS Propagating Plants: How to Create New Plants For Free by Alan Toogood, Royal Horticultural Society

Other Salvias you may also like

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Sources

Sources of information used for this article

Internet

Article from Horticulture Extension University of Wisconsin

Article from Missouri Botanical Garden

Article from Jardin Sec

Vol XII from FloraIberica

Image models from Florandalucia

Books

The New Book of Salvias by Clebsch, Betsy/ Barner, Carol D. (ILT)

Field Guide to the Wildflowers of the Western Mediterranean, Second edition Paperback – 1 Oct. 2021 by Chris Thorogood