Acanthus seeds Seed in a light seed mix in a propogation case at a temperature of 60 F Transplant to a deep loam in full sun, though will grow in ordinary soil & partial shade.
Just to flesh out that process a little more;Sow in standard soil-less seed compost, cover very lightly, water sparingly once, cover with a clear plastic bag, place away from direct sun light in a bright location at 60 degrees F. Germination should take 10 to 20 days. Protect young plants for the first winter. Good luck.