We used to say that all varieties listed here are fairly easy to grow, but as our selection of gentians is expanding, there are some more difficult species among them. To help you, we list the easy ones below. Generally, all like an average garden soil that drains, as is required by most rock garden plants.
You can encounter them easily (unlike Edelweiss) on hikes up in the Alps. Besides the Edelweiss, Trumpet Gentians are the most classic Swiss Alpine flower and shouldn't be missing in any rock garden (really) and are just as breathtaking in a border. The large, deep velvety-blue trumpets are plain irresistible. They also work excellent on steeper hills and can be used as erosion control. Trumpet Gentians are all easy to grow. They like an average garden soil that drains in full sun for cooler climates and mostly sun to dappled shade in hotter ones. Contrary to some literature, they don't need regular watering and are drought tolerant once established.
Our selection can be overwhelming and several are much alike; so we have a few pointers for starters: Our two main varieties are ‘Holzmann’, our best re-bloomer and 'Maxima' and ‘Undulatifolia’ with some of the largest trumpets. To add a couple with distinct differences we recommend angustifolia-Hybrid (Leach) (from Leach Botanical Garden) with its bright blue and dinarica ‘Montenegro’ with the darkest blue and wide, leathery foliage. For us, we get the most blooms in full sun, despite some 100+ deg. F days. As far as growing them, it has been our experience that they prefer to be planted in the garden rather than in pots. They are not fond of potting media and need some plain "dirt". So far we haven't lost a single plant in the garden; in the pots, a different story. So if you do want to grow them in larger pots and planters, make sure to add 1/4 to 1/2 garden soil. We add “Hybrid” to the acaulis/angustifolia selections since they are interbred with different related species. Even in the wild they naturally hybridize and are quite rare in a pure form of a species. This might be bad news for a purist but it makes them much more adaptable to different soil types and conditions.
Other easy to grow gentians are G. asclepidaea, G. paradoxa Hybr. 'Blauer Herold' and G. septemfida var. lagodechiana.
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
Season: April, May
Exposure: Bright Sun, Sun, Light Shade
$19.00
While the lobes are white, the throat and outside of the trumpet are purple infused
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
Season: April, May
Exposure: Bright Sun, Sun, Light Shade
$15.00
Two-tone dark blue and pure white trumpets with a yellow-green interior
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 3: -30ºF through -40ºF, 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
Season: September, October
Exposure: Sun, Light Shade
$8.00
Pure white flowers with yellowish stripes on the outside
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF
Season: September, October
Exposure: Sun, Light Shade
From $7.00
Abundance of deep blue trumpet-flowers, striped on the outside
USDA Hardiness Zone: 4: -20ºF through -30ºF, 5: -10ºF through -20ºF, 6: 0ºF through -10ºF, 7: 10ºF through 0ºF, 8: 20ºF through 10ºF, 9: 30ºF through 20ºF