Sub-shrubby perennials, generally grown on rockeries or on the margins of borders.
Plant in autumn or spring in an ordinary soil in a sunny position. They like a fair amount of moisture. Increase by division of plants in autumn or spring, or seeds may be sown in spring in a liglit sandy soil.
The best to grow in the amateurs garden are: G. cordifolia, blue, June. 1-2 in.
G. nudicaule, pale blue, May-June.
G. trichosanlha, deep blue, May-June.