Centraurea Blue

Bachelor's Button-Perennia/Mountain Bluet

A hardy, clump-forming perennial featuring clear blue, thistle-like flowers held above gray-green foliage in late spring to early summer, with possible rebloom if deadheaded. ‘Blue’ is valued for its reliability, pollinator appeal, and classic color, making it a staple in borders and naturalized plantings.

Size: 18–24 in wide × 18–24 in tall

Zones: 3a–8b
Light: Full sun to partial shade
Soil: Well-drained soils; adaptable to average garden soils
Water: Moderate; drought tolerant once established

Suitable Conditions:



Climate: Performs best in cool to moderate climates



Exposure: Full sun for strongest flowering; tolerates light shade



Soil pH: Neutral to slightly alkaline



Drainage: Essential; avoid consistently wet soils



Spacing: Allow room for clump expansion; divide as needed to manage spread



Notes:



Shape: Upright clumps with a loose, spreading habit over time



Attracts bees and butterflies



Excellent for mixed borders, cottage gardens, and naturalized areas



Can spread by rhizomes; divide periodically to maintain vigor



Generally deer and rabbit resistant

Plant type

Perennial

Height

12-24'

Width

8-12 '

Hardiness zones

3–8

Sunlight

Full sun to part shade

Growth rate

Fast

Bloom time

Spring to summer

Flower color

Blue

Soil

Alkaline, Well Drained

Shape

Clump, Upright

Deer resistant

Yes

Drought tolerant

No