A very old favourite for the rock garden, or even the front of the border or in a container, this plant produces a succession of wide-open, upwards-facing, blue cup-shaped flowers from July to September.
Seeds can be sown at any time but are best sown in winter or early spring to benefit from a cold spell in the wet compost to break their dormancy. We advise covering seeds very thinly with sand or fine grit to about the depth of the seed size. If the seeds do not come up within 6 to 12 weeks the damp seed tray can be given cold treatment in a fridge for about four weeks. They may still take very many months to appear, so please never discard the pot or tray.