Black Button Centaurea is a dramatic reimagining of the classic cornflower, delivering nearly black maroon blooms that look almost sinister in the garden. These double and semi-double flowers emerge on upright plants reaching 36 to 40 inches tall, flowering prolifically over 65 to 75 days from seed. Hardy in zones 4 and thriving in full sun with moderate soil (pH 6.0 to 7.5), this open-pollinated cultivar earns its place as both a stunning cut flower and a magnet for beneficial insects. The compact growth habit keeps plants tidy while their rich, moody color commands attention in any border.
Full Sun
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4-4
40in H x 9in W
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Moderate
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Expect an abundance of double and semi-double blooms in a super-dark maroon that reads as almost black, transforming the familiar bachelor's button into something altogether more dramatic. The tall, upright growth provides weeks of striking color perfect for fresh cutting, while the open-pollinated genetics mean you can save seed year after year. These plants thrive in full sun and frost-hardy conditions, making them reliable performers even in cooler zones, and they attract beneficial insects while requiring minimal fussing.
Black Button Centaurea shines as a cut flower, where its nearly black maroon petals add sophisticated depth to arrangements. The blooms are also edible, bringing visual drama to salads and garnishes. Beyond the kitchen, the flowers actively attract beneficial insects to the garden, making this variety as useful for pollinators as it is beautiful for human enjoyment.
No timeline data available yet for this variety.
Sow seeds indoors 3 to 4 weeks before your planting-out date in cell packs or larger containers. Maintain night temperatures of 50 to 55°F for several weeks to develop a strong root ball. Transplant when seedlings show their first true leaves.
Transplant seedlings outdoors once they have developed a robust root ball, spacing them 9 inches apart. Harden off gradually before moving to the garden to acclimate to outdoor conditions.
Direct seed as soon as soil can be worked in spring. Sow thinly in rows at a rate of about 6 seeds per foot, pressing seeds 1/4 inch into the soil and covering lightly. Keep the soil surface moist until seedlings emerge.
Cut flowers when they are 1/4 to 1/2 open for the longest vase life and most vibrant color. Harvest in the morning after dew dries but before the heat of the day. Use sharp scissors and cut just above a set of leaves to encourage branching and additional blooms.
Deadhead spent flowers regularly to encourage continued blooming throughout the season. The compact, upright growth habit requires minimal pruning, though you may remove lower leaves as the plant matures to improve air circulation and reduce disease pressure.
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