Compact bunches of divided spires of rich sky-blue flowers open over a long period above clumps of thin iris-like leaves. Very long-lived in a well-drained sheltered spot.
For best results, sow immediately onto a good soil-based compost. Cover the seeds with fine grit or compost to approximately their own depth. They can be sown at any time, and germination can sometimes be quicker if kept at 15 to 20 degrees C. We sow most seeds in an unheated greenhouse and wait for natural germination, as many seeds have built-in dormancy mechanisms, often waiting for natural spring germination, hence giving them a full season of growth.