Description and general information
Achillea clavennae is also known as silvery yarrow. They are native top the eastern Alps and the Balkan Peninsula. Plants form low rosettes of divided, fragrant, silvery-pubescent leaves which are partially evergreen. In mid-summer arise stems 15-25 cm that are topped with a flat cluster of white flowers. Prompt dead-heading often results in a second flush of flowers in early autumn.
Cultivation
This yarrow requires well-drained soil in full sun to light shade. They are not fussy in regards to soil pH. Do not over-fertilize as it will encourage lush foliage and few flowers. Plants are reasonably drought-tolerant. They are rated from USDA zones 3-8.
Bloom period
Mid-summer with sporadic blooms through fall.
Propagation
Seed, cuttings or division.
Seed
Seeds may be sown at 15-20 C with no stratification required.
Division
Plants may be dug and divided in early spring in colder zones or in the fall in milder zones.
Cuttings
Plants spread by short rhizomes. Non-flowering sections of rhizome with a rosette attached may be taken as cuttings in summer and root quite quickly.