Rosie O'Day Alyssum is a frost-tolerant annual flower that earns its name through award-winning blooms hardy enough to thrive where other flowers fail. This compact cultivar of Lobularia maritima grows into a neat 4 to 9-inch mound with a 12-inch spread, reaching full flower in 50 to 59 days. It thrives in full sun across hardiness zones 3 through 11, making it equally at home in cool summer gardens, hanging baskets, or tucked into patio containers where its delicate flowers can spill and sprawl.
Full Sun
Moderate
3-11
9in H x ?in W
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High
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Rosie O'Day produces frost-tolerant blooms that persist where tender annuals wither, giving you color deep into the season. The award-winning flowers arrive quickly, in roughly 50 to 59 days from seed, on plants that stay naturally compact and tidy without excessive pruning. Its low, mounding habit and modest 6-inch spacing requirement make it wonderfully suited to dense plantings, window boxes, and hanging baskets where every inch counts.
Rosie O'Day Alyssum grows as an ornamental flowering annual, prized for its delicate blooms in containers, hanging baskets, patio borders, and indoor gardens. Its compact, mounding growth habit makes it excellent for edging beds, filling gaps in mixed plantings, and softening the hard lines of walkways and patios.
No timeline data available yet for this variety.
Sow seeds indoors 4 to 6 weeks before your last spring frost. Press seeds lightly into the soil surface or cover with a thin layer of vermiculite, as they need light to germinate. Keep soil moist and maintain temperatures around 65 to 70 degrees Fahrenheit for reliable germination. Seedlings typically emerge within 7 to 10 days.
Harden off seedlings by gradually exposing them to outdoor conditions over 7 to 10 days. Transplant outdoors after the last frost date, or even slightly earlier, as Rosie O'Day tolerates frost. Space transplants 6 inches apart. Seedlings are robust and transplant easily.
Direct sow seeds outdoors after the last spring frost has passed. Scatter seeds where you want them to grow, press lightly into soil, and keep the soil moist until germination occurs in 7 to 10 days. Thin seedlings to 6 inches apart once they develop their first true leaves.
Rosie O'Day Alyssum's naturally compact, mounding growth habit requires minimal pruning. Deadhead spent flower clusters regularly to encourage continuous blooming and maintain a tidy appearance. Cut back any leggy or sparse growth to promote fuller branching if the plant stretches as temperatures warm.
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