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Mountain Bluet, Perennial Bachelor's Button, Perennial Cornflower, or Mountain Knapweed (Centaurea montana)


Family: Asteraceae (Daisies)
Genus: Centaurea
Species: montana
Type: Perennial
Flowering: May to July; Rebloom Late Summer/Early Fall
Zones: 3-8
Light: Full Sun
Soil: Poor, Dry to Moderately Moist, Well-Drained
Height: 1-2 feet H x 1-1.5 feet W
Propagation: Seed, Division in Spring or Fall
Colors: Blue, Purple, Pink, White
Origin: Europe

Mountain bluet is easy to grow in Iowa due to its tolerance of cool winters. Preferring dry conditions and poor soils, it will bloom throughout early to mid-summer. If cut back after initial flowering, mountain bluet can rebloom from late summer to early fall. Overall, mountain bluet is low maintenance to the point of becoming invasive in the proper environment. If you are seeking a unique flower that will thrive in poor soil, full sun, and drought, mountain bluet is just the right note for your garden arrangement.

Please note that the Zones listed above are USDA Hardiness Zones and are only given as a rough indication of whether a plant will grow and thrive in your area. Temperature variations and unusual weather conditions can affect plant survival. To assist plant survival during the winter, you may wish to place mulch over the areas in question or plant the flowers in an area away from walls or cement. Additionally, digging up bulbs and roots to overwinter indoors may be preferrable to keeping them in the ground.