A family of free flowering annuals and herbaceous perennials. The upright annuals make excellent bedding and the trailing forms are ideal for handing baskets and containers.
Family: Verbenaceae (Verbena family)
Botanical Name: Verbena
Common Names: Vervain, Glandularia
Foliage: Simple toothed lanceolate, oblong or pinnately lobed leaves.
Flowers: Short spikes, panicles or clusters of tiny salver-shaped flowers. In shades of white, scarlet, rose, salmon, deep blue and lavender.
Flowering Period: June to September.
Soil: Moist but well-drained, moderately fertile soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Best in full sun. Grow in a west or south facing aspect.
Habit: Bushy, upright or low growing.
Type: Perennial or annual.
Origin: North and South America.
Hardiness: Perennials are hardy throughout most of the UK. Protect tender annuals from frost.
Vervain flourish in any light, free-draining, reasonably fertile soil, in a sunny open border or container.
Annuals are popular for containers, hanging baskets and bedding schemes. They can be grown from seed but it is much easier to buy annuals from a garden centre or nursery, in spring.
Pinch out the tips of young plants to encourage bushy growth.
Perennials are ideal plants for the rock garden or mixed borders. Tall vareties make excellent cut flowers.
Water during dry weather and water container grown plants daily. Avoid waterlogged conditions.
To improve the flowering of annuals, apply an all-purpose flowering plant food (slightly higher in phosphorus and potassium) every few weeks, or use a slow release form. Do not over fertilize.
Deadhead regularly to extend the flowering period.
Susceptible to attack by slugs, leafhoppers and aphids. Can be affected by powdery mildews in dry weather.
Sow seed under-glass in February/March, at around 18-21°C (64-70°F). Germination can be slow and difficult. Prick out, pot on and harden-off before planting out in late May.
Take cuttings from non-flowering sideshoots of perennials in August-September. Root in a light, sandy compost and overwinter in a light but frost-free place.
The following tender perennial forms are normally treated as half-hardy annuals in UK:
Verbena rigida (slender vervain) a slightly tender form with oblong, deep green leaves and small violet flowers on erect stems, in July-October. Height 12-18in (30-45cm), spread 18in (45cm). For sale at Crocus. 'Alba' is a compact white-flowered strain. Height to 4in (10cm), spread 12in (30cm). 'Santos' is a relatively new, hardier form, with clusters of bright purple blooms. For sale at Van Meuwen.
Verbena tenuisecta (Moss Verbena) is a tender perennial. The variety 'Desert Jewels' is a good trailing form with lacy foliage and pretty flowers in a wide range of colours. Good drought tolerance and easy spreading habit. For sale at Thompson & Morgan.
Verbena x hybrida is a popular bedding form with dark green, lanceolate leaves and tight rounded clusters of blue, purple, red, pink or white flowers from June to October. Height and spread up to 2ft (60cm). Many named hybrids are available, including:
Verbena canadensis is a compact, globular form with dense, rosy-lilac flower heads. Height and spread to 12in (30cm).
Verbena erinoides is a branching plant with finely cut leaves and small blue-violet flowers. Good ground cover. Height to 20in (50cm).
Verbena bonariensis is an upright bushy plant with tall leafless flower stems that create a light, airy effect. The stems are topped with small lilac-blue flower clusters. Height to 40in (1m). For sale at Crocus. Cultivar 'Buenos Aires' has tightly clustered, rich purple florets. For sale at Van Meuwen. 'Lollipop' is a compact form that is perfect for growing in patio pots. For sale at Van Meuwen. 'Royal Dreams' is an even shorter variety with luminescent, mauve-pink blooms in tight, rounded clusters. For sale at Thompson & Morgan.
Verbena hastata (lance verbena) is a long-flowering, upright perennial that produces slender, branching spires, topped with flower spikes throughout summer. Cultivar f. Rosea produces spikes of small, clear pink flowers. Height to 4.5ft (1.5m). For sale at Crocus.
Verbena officinalis (common vervain) is an upright evergreen perennial with lobed green leaves and clusters of two-lipped mauve flowers. Height to 28in (70cm). Var. grandiflora 'Bampton' is a borderline hardy strain with purple-flushed foliage and spikes of small violet-pink flowers, in summer. For sale at Crocus.
Verbena peruviana is a low-growing, spreading rock garden plant with grey-green leaves and brilliant scarlet, star-like flowers in summer. 'Endurascape White Blush' is a pretty white form.
Verbena samira is a fast growing trailing perennial that produces giant flowers throughout the summer. The cultivar 'Deep Red Star' bears striking ruby red flowers, with clean white stripes. For sale at Van Meuwen.