-As of September 25, 2023, theses will come trimmed, with new growth showing for next spring-. The worlds first double gentian! And deep blue at that. Grows in mats of grassy foliage and produces bunches of double trumpet-flowers, striped on the outside. Relatively easy in acidic soil and summer moisture. They take full sun for us with occasional low 100s; for hotter climates afternoon shade is recommended.