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Features
Tall, wirey stems hold heads of tiny, purple-blue, lightly fragranced flowers aloft, above its clump of dark green, deciduous leaves.
What to use it for
Great in borders and prairie style planting, particularly to add height to the back of a border. Attracts insects, particularly butterflies and bees, so it’s perfect for a wildlife garden.
How to look after it
This plant isn’t fully hardy, so it may be damaged or killed by winter frosts. Reduce the risk of this by leaving the stems intact over winter and mulching well in autumn. Cut down the stems when the fresh growth starts in the spring.
How to prune it
Cut back flowered stems in spring or, if in a frost-free area, in autumn after flowering.
How to propagate it
Divide clumps in spring, the divided plants should flower in the same year. You may also find that the plant layers if stems touch the soil; the resulting plants can be detached and potted on.
Semi-ripe stem-tip cuttings can be taken in late summer, preferably from non-flowering stems (if this is not possible, remove any flowers or flower buds from the stems you use). The cuttings should root within 14 days at 15°C and should be kept frost free over winter.
Verbena bonariensis self-seeds freely, and often these seedlings are more resistant to environmental conditions, such as drought, than transplanted plants. Alternatively, seeds can be collected in autumn and sown in spring at 21°C. They should germinate in around 14 days and flower in the same year.
Common problems
Pests rarely infest this plant, but it can be susceptible to powdery mildews.
Other useful information
Has been given the Award of Garden Merit by the RHS.
