Robust, upright perennial, with deeply serrated, prickly grey green leaves whitish beneath. Rounded, violet-blue flower heads on silvery, branched, leafy stems are produced in late summer. Loved by
bees & butterflies. Sun.
Sow from late winter to spring in a good seed compost just covering the seed with compost. Gently firm down compost and seal
inside a polythene bag after sowing. Germination usually takes 10-20 days at 20-25C (70-75F).
When seedlings are large enough to handle, transplant and grow on in cooler conditions. Gradually
acclimatise to outdoor conditions for 10-15 days before planting out, after all risk of frost, 60cm (24in) apart in a sunny spot on light well drained soil.