A large genus of about 400 species, as well as a number of cultivars. The gentians are treasured for their blue flowers, which vary from a deep ‘gentian’ to a very pale shade of blue. Most of the commonly grown plants are blue but there are also white and yellow gentians, as well as the rarer red. The flowers are mainly trumpet-shaped, with a long tube and a flared mouth. However some species are more cup- or star-shaped.
Some are relatively short and grow no more than a couple of centimetres high. These are most suited to rock gardens, or pot culture. Others are much taller and can be used in the open border or even in woodland situations. Gentians are not the easiest of plants to grow and many gardeners accept this as a challenge. Most prefer acid soils, which should be fertile and moisture-retentive but at the same time free draining. While many should be planted in an open situation, it is best to avoid places where they receive the hot mid-day sun. A lightly shaded position suits most. Increase from seed, from division, or cuttings taken in spring.