General Culture:

Best grown in poor to moderately fertile, dry to medium moisture, well-drained soils in full sun. Excellent soil drainage is essential for growing this plant well. Does poorly in moist to wet soils where plants are susceptible to root rot. Plant stems tend to lodge (fall) in summer, especially if grown in fertile soils and/or part shade. General foliage decline commonly occurs in high humidity summer climates such as the St. Louis area. Consider pinching back stems in late spring to reduce mature plant height. If foliage declines or stems flop in summer, plants may be sheared to revitalize. 'Silver Frost' may spread somewhat aggressively in the garden by rhizomes, though it appears to be more restrained than the species. Soil barriers may be considered if growing it in borders close to other valuable perennials.

Noteworthy Characteristics:

'Silver Frost' is a compact cultivar which features stems and leaves that are silvery-white and pubescent. It is a generally upright perennial that is grown for its attractive foliage which adds contrast to gardens. The tiny, somewhat inconspicuous, yellowish-gray, discoid flower heads (rays absent) which appear in dense panicles at the stem ends in summer have little ornamental value. 'Silver Frost' typically forms a spreading clump of generally erect, non-woody stems to 18" tall, with the clumps creeping outward by rhizomes to 2-3' wide. Lance-shaped leaves (to 4" long) may have jagged marginal teeth. Foliage is aromatic when bruised. Species is native to the western United States including Missouri.