They should be given full sun and a deep, light soil. Good drainage throughout the cultivation is essential as the plants easily get root rot if grown in too wet conditions. They have a long taproot and transplanting has to be done with care. Blooming has started in my garden in the first half of August and continued until frost. Regular cutting of the flower stems will produce abundant material for drying.
Seeds are available from most seed companies.
Limonium bonduellii is a similar species from N Africa with yellow flowers.