Bonita Top Blue Aster brings pure, luminous color to late-season gardens with its deep blue flowers held on sturdy, upright stems 24 to 30 inches tall. This open-pollinated cultivar of Callistephus chinensis thrives across hardiness zones 2 through 11, making it accessible to gardeners nearly everywhere. With moderate water needs and a preference for full sun to partial shade, it's a straightforward grower that rewards minimal fuss with abundant blooms perfect for cutting.
Partial Sun
Moderate
2-11
30in H x 18in W
—
High
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The deep blue flowers are the heart of this variety, appearing in profusion on compact, well-branched plants that stay tidy without excessive pruning. Unlike sprawling aster varieties, Bonita Top Blue holds its upright habit naturally, reaching a mature width of just 12 to 18 inches while climbing to 24 to 30 inches in height. This restrained growth habit and prolific flower production make it surprisingly reliable even for gardeners new to asters.
Bonita Top Blue Aster is grown primarily for cutting and arrangement work, where its tall stems and vibrant blue flowers bring depth and color to bouquets and floral designs. The upright growth habit and prolific flowering also make it valuable for garden backgrounds, borders, and late-season color when many other flowering plants are fading.
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Start seeds indoors 6 to 8 weeks before your average last frost date. In mild climates, start in late summer for winter bloom. Germinate at 65°F.
Transplant outdoors 1 to 2 weeks after your average last frost date, when soil temperature reaches at least 65°F. Space plants 12 inches apart. In mild climates, transplant in late summer for winter bloom.
Sow seeds directly outdoors 1 to 2 weeks after your average last frost date, when soil temperature is at least 65°F. In mild climates, sow in late summer for winter bloom.
Pinch back young plants when they reach 6 inches tall to encourage branching and fuller growth. Remove spent flowers regularly to extend bloom time throughout the season. The naturally upright habit requires minimal pruning beyond these basic techniques.
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