Overview of Verbena bonariensis
Clusters of small purple flowers atop airy stems tempting passing butterflies to stop for a sip is just one reason to consider adding Verbena bonariensis, also called tall verbena or purpletop verbena, to your garden. This plant is just one of about 250 species in the genus Verbena, of which only about half a dozen are in cultivation. V. bonariensis is native to Brazil and Argentina, and the specific epithet refers to Buenos Aires.
This species was first grown as a garden ornamental in 1726 by Englishmen James & William Sherard, who got the seeds from a dried specimen sent back to England from Buenos Aires. This plant is a tender perennial (hardy in zones 7a to 11b) that is commonly grown as an annual in cooler climates. It is considered a weed in many mild climates, such as California, Texas, Australia and southern Africa, where it has naturalized. It is not overly aggressive in Wisconsin and other cold climate areas.
Purpletop verbena is an upright, clump-forming plant with wiry, widely branched stems. The species grows 3 to 6 feet tall and 1 to 3 feet wide. Unlike many other tall herbaceous plants, it has sturdy stems and is unlikely to flop over. The stiff stems and branches are square and textured like sand paper. The deep green, lance-shaped serrated leaves form a mounded rosette at the base of the plant, with few on the stems. The flowers are borne in rounded clusters 2 to 3 inches across. The individual flowers are little purple or rosy lavender tubes, about ¼ inch across. It blooms from mid-summer until the first frost.
The flowers are highly attractive to butterflies, hummingbirds, and other pollinators. The airy habit of this plant makes it a good choice for the front or middle of the border. Despite being tall, the sparce, upright habit allows plants behind purpletop to show through. It is best planted in masses or groups, to ensure it attracts attention. They are perfect in a cottage garden mixed in with other plants. Its flowers combine effectively with yellow, orange, or pink flowers. Interplant V. bonariensis and plants like purple basil or purple coneflower for an interesting monochromatic display.
When used as cut flowers, stems last well in flower arrangements.
Propagating Verbena bonariensis
V. bonariensis is easy to grow from seed indoors or from volunteers in the garden. Start seeds indoors 8 to 12 weeks before the average date of last frost. Cover the seeds with a thin layer of seeding mix, as they need darkness to germinate. Germination can be somewhat slow and irregular.
Outdoors, don’t disturb the soil too much in spring if you want the volunteer seedlings. Seedlings take a while to germinate, especially in our colder climate (they may not appear until as late as June). Pinching the first few shoots of the young plants will encourage branching and create a more compact, shrub-like plant. They can also be left in their natural, open form. Either place transplants or thin volunteers to about 2 feet apart.
As purpletop often reseeds in favorable sites, when not deadheaded, volunteer seedlings can be thinned to allow some plants to remain, transplanted to new garden locations, or pulled or hoed out in early spring.
When transplanting volunteers, leave as many roots intact in a soil mass for best results. The plants will droop when their roots are disturbed, but they will recover once established. Kkeep transplanted volunteers well watered until they are re-established.
Landscape Use of Verbena bonariensis
Plant V. bonariensis in full sun and well-drained soil. It is fairly drought tolerant and doesn’t require watering once established (except in periods of drought). Although it will grow acceptably in poor soil, it will thrive in fertile soils with high organic matter content.
This species has few insect or disease problems other than powdery mildew. Mildew infection causes white spots on the leaves, but does not cause significant damage to plants. Plants are resistant to damage by deer and rabbits.
Cultivars of Verbena bonariensis
Breeders have itntroduced varieties with improved branching and more compact habits. These include:
- ‘Flair’ is very compact and well-branched seed variety, growing 26 inches tall and 16 inches wide. It is floriferous, with bright viuolet flowers. It grows well in both containers and in the landscape.
- ‘Lollipop’ is a vegetative selection that grows 20 to 24 inches tall and wide, with a long bloom period.
- METEOR SHOWER® (variety ‘INVEBPUTOW’) is a vegetative Proven Winners® variety that grows 20 to 30 inches tall and 8 to 12 inches wide.
- ‘Vanity’ is a seed propagated variety that grows 30 inches tall with improved branching. It is a 2022 All-America Selections Winner.
Author: Susan Mahr, University of Wisconsin—Madison
Reviewers: Bruce Spangenberg, Horticulture Outreach Specialist, Allen R. Pyle, Horticulture Outreach Specialist, UW—Madison Extension
Revised: May 2026
