Overview of Silver Sage
Silver sage, Salvia argentea, is just one of over 900 species of salvias. Unlike most in the group that are grown for their flowers, silver sage is prized for its eye-catching, fuzzy silver leaves. Children and adults alike have a hard time resisting petting the soft, appealing foliage.
Native to dry, stony grasslands of southern Europe, the eastern Mediterranean and northwest Africa, this plant is hardy in zones 5a to 8b. It tends to be a short-lived perennial in dry areas and/or if the flowers are removed, but is more typically a biennial in humid climates, especially if allowed to go to seed.
The plant grows a low basal clump or rosette of leaves up to 1½ feet across. Leaves emerge crinkled but flatten as they grow, with the margins retaining a sinuous wave. The large, irregularly lobed oval leaves are densely covered with silver hairs that create an attractive, furry or wooly look.
In the winter the plant dies back mostly to the ground, but it is best to leave the old leaves on the plant (even though this does not look very good) until new growth resumes the following spring. The large leaves help shield the crown from excess moisture, keeping the soil around the base drier and helping winter survival.
Silver sage flowers in early to mid-summer after its first year. Although the two to three foot candelabra-like flower spikes can be dramatic, the conspicuous white or green bracts and small white or yellowish flowers are not particularly impressive.
Flowering causes the foliage to deteriorate and weakens the plant, so for the best foliage show, remove flower spikes while they are still small and before seed is produced, unless you wish to propagate the plant.
Landscape Use of Silver Sage
Use silver sage as a specimen plant, an accent plant in the rock garden, or at the front of a border in dry, sunny sites. A grouping of these plants makes a stunning ground cover. Silver sage combines well with other drought tolerant plants, such as lavender, yarrow (Achillea) or Russian sage (Salvia yangii, = Perovskia atriplicifolia).
It is a good complement for purple or magenta flowers and looks gorgeous in a white themed garden.
General Care of Silver Sage
Silver sage grows best in fertile, well-drained soil in full sun to partial shade. Hairy-leaved plants and high humidity often do not go together. In the Midwest, full sun and very well-drained soil, especially in winter, is needed for plants to thrive.
Silver sage can also be grown in containers. Space new plants in the ground two to three feet apart.
Aphids can occasionally be a problem, and in damp conditions slugs can devastate the leaves, but otherwise silver sage has few problems.
Propagating Silver Sage
Plants are easily grown from seed, and self-sown seedlings may result if plants are allowed to flower. Sow purchased or collected seed indoors in early spring for planting out after danger of frost has passed. Silver sage can also be propagated by removing side shoots with roots from older plants in the spring.
– Susan Mahr, University of Wisconsin – Madison
