Common Name: dusty miller
Type: Herbaceous perennial
Family: Asteraceae
Zone: 6 to 9
Height: 0.75 to 1.00 feet
Spread: 1.00 to 1.25 feet
Bloom Time: June to August
Bloom Description: Yellow
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Annual
Leaf: Colorful
Tolerate: Drought, Dry Soil, Shallow-Rocky Soil
Culture
Best grown in very well-draining, poor, evenly moist to dry soils in full sun. Avoid overly rich or moisture retentive soils. Tolerant of heat, drought, wind and salt spray. Hardy in Zones 8-11.
'Balcentsirl' offers improved cold tolerance compared to the species and is hardy in Zones 6-9
Noteworthy Characteristics
Centaurea ragusina, commonly called Croatian centaury, Dubrovnik knapweed, snowflake dusty miller, and silver knapweed among many other common names, is a herbaceous perennial endemic to cracks and crevices in seaside, limestone cliffs in the Dalmatia region of southern Croatia. Its native range may have extended to other areas of southern Europe in the past, but today it is considered naturalized in Italy and France. Mature plants will reach 0.5-2.25' with a similar spread and a rounded or mounding, well-branched growth habit. The elliptic leaves have several deep, rounded lobes and will reach 3-6" long and 0.75-1.5" wide. The 1-1.5" wide flowerheads emerge in summer on the ends of upright, leafless flowering stalks. The flowerheads are made up of bright yellow disk florets and lack ray florets. The flower stalks, stems, and leaves are all covered in a thick, velvety layer of hairs, giving them a white appearance.
Genus name comes from the Greek word kentauros meaning centaur.
The specific epithet ragusina refers to the Croatian city of Ragusa, today known as Dubrovnik, which is located on the far southern coast of Croatia.
The common names for this species typically refer to either the native range of this species or its white foliage.
'Balcentsirl' is a compact selection of Croatian centaury that features bright white-grey foliage with wavy margins. Mature clumps will reach up to 12" tall and 14" wide. This cultivar is primarily grown for its showy foliage rather than its flowers, but they are similar in appearance to the species. Commonly sold at nurseries and garden centers under the name SILVER SWIRL.
Problems
Root or crown rot is possible in poorly drained, overly wet soils.
Uses
Suitable for use in rock gardens, Mediterranean gardens, seaside gardens, retaining walls, and containers.