The Verbena genus is large, contains both annuals and perennials, and has a range in height from 10 cm through to 1.4 m.
In genral they have dark green toothed leaves, and bloom from summer until the first frost of winter.
When in bloom Verbena carry clusters of tiny flat fragrant flowers that attract butterflies and bees to the garden.
Check out the specific 'how to grow Verbena bonariensis' (Purpletop Vervain) guide.
Photographs of Verbena rigida - Veined Verbena (above) and Moujean tea (below)
One of the commonest names of garden grown Verbena is Vervain, other commonly grown species include veined Verbena, Purpletop, and Moujean tea.
Common Names: Vervain, Verbena, Purpletop.
Life Cycle: Hardy annual. Half hardy perennial, hardy perennial.
Height: 4 to 47 inches (120 cm).
Native: Northern America, Europe.
Growing Region: Annuals: zones 1 to 10. Perennial: zones 3 to 10.
Flowers: Late spring until first frost.
Flower Details: Blue, violet, white, purple, rose, pink. Small. Five petals. Clusters. Spikes. Fragrant.
Foliage: Simple. Opposite. Hairy. Ovate. Lanceolate. Sometimes lobed; toothed.
Sow Outside: Cover stratified seed. Following last frost. Spacing 6 to 40 inches (15 to 100 cm).
Sow Inside: Mix seeds in a growing medium, place in a freezer bag, keep moist, then stratify by refrigeration for two weeks. Germination time: two weeks to three months. Temperature 70°F (21°C). Nine or ten weeks in advance. Transplant outdoors a few weeks after the the last frost; minimum temperature should not drop below 50°F (10°C).
Requirements: Full sunlight or light shade. Good drainage. Soil pH 6 to 7. Rich soil. Can survive in dry soils. Feed in spring. Regular watering. Pinch tips. Deadhead. Perennials should be brought indoors over winter in cold areas. Propagate: cuttings in the spring.
If growing Verbena outdoors from seeds, then sow out following the last frost of spring, then lightly cover the seed. Due to the large variety in Verbena size the spacing is species dependent, in general plant small Verbana about 20 cm apart, medium at 30 to 40 cm, and larger plants at 60 cm to a metre apart. Ideally Verbena plants should be grown in a fertile soil that is slightly acidic to neutral (pH 6 to 7). They like to grow in sunny part of the garden, but can tolerate partial shade if needed.
If growing Verbena indoors first then sow about two months before the last frost. The Verbena seeds should first be sown into a pot; next cover with a plastic bag; put in the fridge for two weeks; then allow to germinate in the dark at a temperature of 18 to 24 degrees centigrade.
Seeds should take from two weeks to three months to germinate. Transplant the young Verbena plants outdoors a few weeks after the last frost of spring.
It is pretty easy to care for Verbena plants; remove the tips of young Verbena to encourage branching; they like dry soil but water them during prolonged dry spells; give them a couple of feeds in the spring; deadhead flowers to prolong the flowering period. If you require more plants then propagate Verbena by taking cuttings; this can be done in either spring or at the start of autumn.