Verbenas are wonderful clump-forming plants producing elegant spikes or flat-topped heads of small flowers on stiff stems. Depending on their growing habit, these hardy perennials can be used to bring vertical dimension to the middle or back of the border or add an exquisite touch of colour to the front of a border. Long lasting and nectar-rich, their flowers are a magnet for pollinating insects and are particularly suited for bouquets. Try mixing with grasses or with other perennials such as achilleas, echinaceas, eryngiums, nepetas, rudbeckias and thalictrums. Alternatively, interlace with dark-leaved white or deep red dahlias.
Plant in moist, well-drained, moderately fertile soil in full sun. Provide mulch in winter, especially in frost-prone areas.
Verbenas are supplied in 9 cm pots. Always unpack on arrival and store in a cool place until ready to plant.
Potential problems, pests and diseases:
Aphids:these sap-eating insects can weaken plants and spread viruses. Whenever possible, pick off by hand using gloves.
Leafhoppers:these sap-eating insects can cause the leaves to become mottled with white to brown spots. Heavy attacks can lead to defoliation.
Snails and slugs:these pests enjoy munching on young shoots, stems, leaves and flowers. Watch out for damage!
Thrips:these sap-eating insects like to feed on leaf and flower tissues. Leaves and petals become mottled with white/discoloured spots and heavy attacks may cause buds to fail to open. Thrips thrive in dry, hot weather and can spread viruses! Keep plants regularly watered and dispose of any deceased plant material and debris ahead of the growing season to prevent any risks of infestation.
Powdery mildews:these fungal diseases usually caused by planting in the shade or by poor air circulation can be seen in the form of white, powdery coating on the leaves. Cut off any infected material before disinfecting your scissors.