This Brazilian vervain (Verbena bonariensis 'Buenos Aires'), a nonhardy perennial, differs from the straight species by having larger lavender-lilac flowers on shorter flowering stems. The plants reach close to 3 feet in height by the end of the growing season in Chicago-area gardens. Their honey-like fragrance is a powerful attractant for pollinating insects and hummingbirds. Plant this perennial in full sun.

In USDA Zones 7 to 10, gardeners should deadhead the flowers to prevent seedlings from establishing in natural areas.