Nierembergia: Cup flower
Height 15-20cm (6-8in)
Planting distance 20cm (8in)
Flowers early summer to early autumn
Moist, but well-drained
Sunny sheltered site
Tender perennial grown as half-hardy annual
Though perennial, the species most commonly grown in Britain, Nierembergia caerulea, is tender and usually treated as an annual. Its fine green foliage forms neat hummocks which become covered with small pale lavenderwith yellow throats from early summer to early autumn. ‘Mont Blanc’ is smothered with glistening white flowers; ‘Purple Robe’ has deep violet flowers. Cup flower looks most effective as edging to and is ideal for container growing.
Sow the seeds in pots or pans under glass in late winter or early spring at a temperature of 15°C (59°F). Prick out the seedlings into boxes and harden off before planting out in late spring.
The plants will grow in ordinary soil, although a moist but well-drained soil gives the best results. Choose a sunny sheltered site.
Pests and diseases