Handsome individual spikes of blue flowers on tall strong stems sparsely clad with encircling leaves. In autumn, all leaves turn bright yellow, and this was how we spotted it through the trees when collecting seed on Sakhalin Island, Russia (RBS0290).
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.