Verbena bonariensis (Purple Top Vervain)

Verbena bonariensis is a much-loved architectural perennial, with tall, wiry stems topped by lilac-purple flower clusters that appear to float above the border from summer into autumn.Its open, airy habit threads beautifully through grasses and herbaceous planting without blocking the view, while the nectar-rich flowers are especially valuable to bees, butterflies and other pollinating insects.Plant in full sun in moderately fertile, moist but well-drained or well-drained soil. It is particularly effective in cottage gardens, prairie-style planting, wildlife borders and generous naturalistic drifts.Water while plants establish and during prolonged dry spells. Leave the stems for winter structure if desired, then cut them down in spring as fresh growth emerges from the base.