Product Field NotesCompanion Plants
Buzz Stop Ironweed: Late Purple That Takes Over After Harvest
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Buzz Stop ironweed is a sturdy, full plant with broad clusters of fluffy, dark rosy purple flowers on near-black stems in late summer and early fall. Its narrow, deep green leaves have a silvery sheen and are among the darkest in the group, so the flowers stand out sharply.
It grows happily in the same full sun and lean soil as lavender. Its main gift to a lavender garden is timing: it blooms from mid-August into fall, keeping purple in the garden long after the lavender has been cut.
Buzz Stop at a glance
| Trait | What to expect |
|---|---|
| Botanical name | Vernonia 'Buzz Stop' |
| Flowers | Dark rosy purple clusters, 4 to 6 inches wide, on near-black stems |
| Foliage | Narrow, deep green with a silvery sheen |
| Size | About 42 to 48 inches tall, 48 to 54 inches wide |
| Bloom | Starts mid-August, peaks early September, about six weeks |
| Hardiness | USDA zones 4 to 9 |
| Light | Full sun |
| Wildlife | Excellent for pollinators; deer resistant |
The late-season purple
Most lavender gardens have a quiet stretch in late August. The lavender has been harvested or has faded, and the bed is mostly silver foliage. Buzz Stop fills that gap with six weeks of rosy purple clusters that butterflies and bees visit in large numbers, just when many other flowers are finishing.
This is a big plant, about four feet tall and even wider, so it belongs at the back of a sunny border, at the far edge of a lavender planting or in a prairie or meadow bed. Keep it on the north or east side of the lavender so it does not shade the lavender for long. Map it out in the Companion Plant Planner.
Planting and care
- Soil: average. It adapts to dry or moist ground, so it can also sit lower in the yard or in a rain garden.
- Water: through the first season; very heat tolerant once established.
- Space: allow four feet or more between it and its neighbors.
- Fall and winter: leave the stems and seed heads standing for winter interest.
- Spring: cut stems back in early spring.
- Problems: generally trouble-free. It resists mildew well, though rust and leaf spot occasionally appear on ironweeds.
Cutting
Buzz Stop rates well as a cut flower. Its dark purple clusters on black stems bring a deep, moody color to late-summer bouquets, and they look good with the last few stems of reblooming lavender.
Plug tray or bare root
Buzz Stop is offered as a 72-cell plug tray, suited to meadow plantings and growers, and as a bare root plant for a home border. See each product page for current availability.
Frequently asked questions
Is ironweed a native plant?
Ironweeds are native prairie plants. Buzz Stop is a selection chosen for a sturdy, full habit and dark foliage.
Will it spread?
It grows as a large clump. Give it plenty of room and it will fill its space without wandering.
Do deer eat it?
Deer tend to leave it alone.
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