Hardy plants, mostly cultivated as border plants, although the dwarf kinds may be grown on the rockery.
Plant in autumn or spring in a compost of loam, peat, broken limestone and coarse sand in a sunny situation. They like plenty of water during the summer, but should be kept as dry as possible in winter.
Top dress in spring with well-rotted leaf-mould. Increase by division of plants in spring. Seeds may also be sown at the same period. They will probably take about two years to germinate, and should be kept moderately moist.
Gentiana asclepiadea is a variety which succeeds best in a sunny situation. It bears purple-blue flowers on stems 3 ft. in height. July-September.