From uniform and compact plants rise silvery erect stems bearing many silver-green calyx, from which a firework of small clear blue flowers emerge. Height: 35-45cm (14-18in).

Sow in February/March on the surface of a good seed compost. Make sure that the compost is moist but not wet and seal in a polythene bag until after germination which usually takes 2-3 weeks at 18-25C (65-75F). Do not exclude light which is beneficial to germination.

Transplant when large enough to handle into 7.5cm (3in) pots and grow on in cooler conditions. Gradually acclimatise to outdoor conditions for 10-15 days before planting out after all risk of frost, 30cm (12in) apart in a sunny spot in ordinary garden soil.