Buzz Stop is a sturdy, full ironweed that opens dark rosy purple flower clusters on near-black stems in late summer and early fall. Its deep silvery green leaves are among the darkest in the group, a strong backdrop for the flowers.
It grows about 4 feet tall and wide, so give it room at the back of a sunny border or in a prairie planting. It resists mildew well and draws butterflies and bees in large numbers late in the season.
What it looks like
Broad, flat to domed clusters 4 to 6 inches wide of small, fluffy, thistle-like flower heads in dark rosy purple, held on near-black stems at the top of the plant. Leaves are narrow, lance-shaped and finely toothed, 4 to 6 inches long, deep green with a silvery sheen. The plant forms a sturdy, full, upright clump 42 to 48 inches tall and 48 to 54 inches wide. At peak it looks like a big dark green shrub topped with deep purple fluff on black stems.
Growing it with lavender
Ironweed grows happily in the same full sun and lean soil as lavender, and its late rosy purple flower clusters make a tall backdrop that keeps purple in the garden long after the lavender harvest.
Care
Plant in full sun in average soil; it adapts to dry or moist ground and handles heat well once established. Hardy in zones 4-9; leave the seed heads standing for winter interest and cut the stems back in early spring.
At a glance
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Botanical name: Vernonia
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Flower color: Dark rosy purple
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Foliage: Deep silvery green
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Growth habit: Sturdy, full, upright clump
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Mature size: 42 in–4 ft tall × 4 ft–54 in wide
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USDA hardiness zones: 4–9
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Light: full sun
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Bloom start: Mid-August
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Peak bloom: Early-September
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Bloom pattern: Long Blooming
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Deer resistance: Resistant
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Pollinator value: Excellent
Sizes and shipping
Dormant bare-root plant, sold in boxes of 25 per variety (order in multiples of 25). Bare-root plants ship or are picked up March 1–May 31 only. They are soil-free, so they may ship to every state in that window. Dormant plants often show little or no top growth on arrival; plant or heel them in promptly.