From early summer to first frost, the South America verbena (Verbena bonariensis) provides hazy, soft color in the garden. Once you see this delightful plant with its tall, wiry stems dotted with tiny lavender blooms, you won't forget it. Small blooms stand out against sparse, narrow leaves that appear along the open, branching stems. Verbena is prone to leaning over when planted alone, so support it with sturdy perennials such as Shasta daisy (Leucanthemum x superbum) and asters. Verbena readily self-seeds in warmer climates, so deadhead the blooms before seeds form.

Plant Facts
Common name: South America verbena, Brazilian vervain, Brazilian verbena
Botanical name: Verbena bonariensis
Height: 4 to 6 feet
Plant type: Clump-forming tender perennial
Zones: 7 to 11
Family: Verbenaceae

Growing conditions

  • Sun: Full sun
  • Soil: Prefers well-drained, moderately fertile soil. Tolerates infertile soil if it's well drained.
  • Moisture: Average moisture

Care

  • Mulch: In zones where verbena is borderline hardy, mulch roots for winter protection.
  • Fertilizer: None required. In rich soil, verbena will flop over.
  • Pruning: Deadhead to deter self-seeding.

Other species

  • Rose vervain (Verbena canadensis) is a butterfly-attracting native to the eastern United States. Panicles of rose-pink, white, or purple flowers bloom late spring until fall. Grows 8 to 16 inches tall. Zones 6 to 8.
  • Blue vervain (V. hastate) is a perennial with 2- to 6-inch spikes of violet-blue or pink flowers (occasionally white) from summer to early fall. It occurs along moist streambeds and roadsides in Eastern North America. Grows 2 to 7 feet tall. Zones 3 to 9.
  • Hoary vervain (V. stricta) is a perennial with 12-inch-long, deep lavender spikes. It's also called woolly vervain because of its fuzzy foliage. Grows 3 to 4 feet tall. Zones 4 to 7.


Garden notes

  • Other good companions for verbena include the perennial cornflower (Centaurea montana) and coneflower (Rudbeckia spp.).
  • Use in a wildlife garden to attract butterflies.
  • Stems are attractive in a cut-flower arrangement.


Pests and diseases

  • Powdery mildew occurs when verbena is planted where there is poor air circulation or excessive moisture.
  • Propagation
  • Sow seeds into the garden after last frost. For early blooms, start indoors six to eight weeks before the last day of frost.
  • In climates where it's a perennial, divide in spring.


All in the family

  • The shrub verbena (Lantana camara) has several interesting cultivars. ‘Fabiola' has salmon-pink and yellow flowers and ‘Radiation' has bicolored orange and red flowers. Both grow 3 to 6 feet tall.
  • The chaste tree (Vitex agnus-castus) has small, pink, purple, or white fragrant flowers, similar to the butterfly bush. Because its foliage resembles marijuana, it's sometimes called the hemp tree. Grows 6 to 25 feet tall. Zones 6 to 9.

Text by Mary Pestel, photo by Tracy Poser