Verbena Bonariensis Growing Guide


Common Name Tall Verbena, Purpletop Vervain
Genus  Verbena 
Species V. bonariensis 
Family Verbenaceae
Life Cycle  Tender perennial, often grown as an annual in cooler climates.
Tray Size  125
Plug Care Plant plugs soon after arrival to avoid stress. Keep the soil consistently moist but not waterlogged during establishment. Avoid allowing plugs to become root-bound or exposed to extreme heat or drought stress before planting. When planting, ensure the crown of the plant is level with the soil surface, not buried.
Netting / Staking Not typically required as Verbena bonariensis has naturally strong, upright stems. However, in windy areas or high-density plantings, light staking or a single layer of netting may help prevent lodging.
Temperature Range

Ideal temperatures: Daytime 65–75°F and nighttime 55–60°F. Plants are frost-sensitive and should be protected from freezing temperatures. In warmer climates (Zones 8–10), it can overwinter without protection. In northern zones, treat as an annual or provide heavy mulch for marginal success. It will self-seed in all zones.
Spacing Field planting: 12–18 inches apart.
Greenhouse planting: Slightly closer at 10–12 inches apart in a checkerboard pattern.
Soil Preference Prefers well-draining, sandy or loamy soil with moderate organic matter. A slightly acidic to neutral pH (6.0–7.5) is best. Avoid heavy, poorly draining soils. Regular but moderate irrigation is recommended, as plants tolerate brief periods of drought once established.
Day Length Facultative long-day plant. Performs best with full sun but tolerates partial shade. High light conditions are ideal for robust growth and flowering.
Pinching Pinching is optional. If a bushier, fuller habit is desired, pinch back young plants 2–3 weeks after planting, removing the top inch of growth. This will encourage branching and more flower stems.
When to Plant Zone 8 and warmer: Plant in the fall for an early spring bloom or in spring for summer blooms.
Zone 7 and cooler: Transplant outside after the danger of frost has passed.
Harvesting Harvest stems when approximately 70–80% of the florets on a spike are open. Use clean, sharp snips or a knife to cut stems at the base. Leave at least 2–3 pairs of leaves on the plant to encourage continued flowering.
Post Harvest Care Immediately place stems in clean water.
Floral preservatives are not essential but can extend vase life.
Store cut stems in a cooler at 40°F. Verbena bonariensis has a vase life of approximately 7 days.
Diseases / Insects Susceptible to powdery mildew, especially in humid conditions. Ensure good air circulation and avoid overhead watering.
Scout regularly for aphids, whiteflies, and spider mites, which are common pests. Treat promptly with insecticidal soap or appropriate biological controls.
Bailey's Notes Verbena bonariensis is a favorite for pollinator gardens and naturalistic designs. Its airy, open structure makes it ideal for filling vertical space without crowding neighboring plants. It’s a great filler for bouquets and has a charming, wildflower-like appeal. This vibrant accent flower makes boring bouquets pop. It's rough and thin stems can make harvesting a chore. Try mowing down the whole plant and letting it re-grow.
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