Tall verbena
Also known as
Purpletop vervain, Argentinian vervain, Purpletop, Verbena-on-a-stick
Keep this plant’s care guide close at hand.
Get the appAbout Tall verbena
Verbena bonariensis, commonly called tall verbena or purpletop vervain, is an airy, architectural perennial valued for its see-through habit and long season of bloom. Slender, wiry stems rise 3–6 ft (0.9–1.8 m) and carry candelabra-like clusters of small lavender-purple flowers from midsummer to frost. The sparse foliage keeps sightlines open, making it ideal for weaving through borders, prairies, and meadow plantings without overwhelming neighbors. Native to South America, it is short-lived but often persists through prolific self-seeding. It thrives in full sun, well-drained soils, and tolerates heat, drought, and poor fertility once established. The nectar-rich flowers are a magnet for butterflies, bees, and hummingbirds, enhancing biodiversity in wildlife-friendly gardens. While generally well-behaved in many regions, it can self-seed aggressively and is classified as a weed in some warm climates—check local guidance. Its minimal maintenance requirements, pollinator appeal, and ethereal structure make it a favorite for naturalistic and contemporary garden styles.
Taxonomy
Properties & Requirements
How to care for Tall verbena
Water
Water new plants deeply 1–2 times per week for 4–6 weeks so moisture reaches 6–8 inches deep, aiding root establishment. Once established, it is drought-tolerant; irrigate only during extended dry spells, giving a thorough soak every 10–14 days. Allow the top 1–2 inches of soil to dry between waterings and avoid waterlogged or compacted sites. Containers dry faster—water when the top inch is dry, then let excess drain freely. Morning watering helps foliage dry quickly and reduces disease pressure.
Light
Provide full sun—at least 6–8 hours of direct light daily—for the strongest stems and heaviest flowering. In very hot climates, a touch of late-afternoon shade is acceptable, but too much shade causes lanky growth and fewer blooms. On balconies or indoors, use the brightest south or west exposure and rotate pots for even growth. Maintain good air movement in sunny, open positions to minimize powdery mildew. Deep shade and excessively rich soils encourage floppiness and diminish the plant’s see-through appeal.
Nutrients
Tall verbena blooms best in moderately fertile to lean soils; excess nitrogen promotes floppy, leafy growth at the expense of flowers. At planting, mix in a small amount of compost for structure, then skip routine feeding in-ground. If plants appear pale or stunted in spring, apply a light dose of balanced, slow‑release fertilizer (e.g., 5‑5‑5). For containers, feed with a half-strength balanced liquid every 4–6 weeks from spring to midsummer. Avoid high-nitrogen products and stop fertilizing after midsummer to prevent weak, leggy growth.
Temperature
Reliable as a perennial in USDA Zones 7–11; elsewhere it is often grown as an annual or reseeds to return. Ideal growth occurs at 65–85°F (18–29°C). Plants tolerate summer heat and humidity if drainage is sharp. Light frosts may scorch foliage; hard freezes below about 14°F (−10°C) usually kill top growth, though crowns may overwinter with mulch in mild winters. In Zones 5–6, rely on self-sown seedlings or provide winter protection and sheltered microclimates to improve survival.
