Trumpet gentian voted local perennial of 2018
The trumpet gentian (Gentiana acaulis) was chosen as the 2018 Calgary perennial plant of the year by voters at the Calgary Horticultural Society’s 2017 Garden Show. Visitors’ hearts were won by the spectacular true blue flowers that made this species a real show stopper at the booth all weekend.
Gentiana acaulis is a native of the mountainous regions of the Carpathians, Pyrenees and Alps. It is a species of the Gentiana genus, so named in honour of Gentius, a king of Illyria in 180 BC, who is credited with the discovery of the herbal properties of these plants.
Gentiana acaulis is part of the Gentianaceae family, which has some 16 genera and 1,600 species that are mostly native to the northern temperate zones around the world.
The species epithet acaulis means “stemless,” as the large trumpet-shaped blue flowers seem to arise directly from lowgrowing mats that spread 20 to 30 centimetres, with evergreen basal rosettes of narrow lanceolate leaves.
The upturned terminal flowers are actually not stemless but grow on short peduncles, and if you look deep into the throat of the true blue, five-petalled flowers, you can see green spots.
The trumpet gentian has been under cultivation since the late 1800s and has proven itself to be a terrific plant for rock and alpine gardens, requiring little care once established. As a highaltitude species, it is valued in Calgary gardens for its hardy Zone 2 rating.
This is a plant that is not fussy about sun exposure, growing equally well in the Reader Rock Garden in full sun and under the drip line of my Colorado Spruce with only morning sun. The key is that it really needs rich, moist, but well-draining soil that is slightly acidic.
Given our alkaline clay soil, the best advice is to amend your soil with a mix of peat and compost before planting, then mulch to conserve moisture and protect the plant’s roots from the hot sun.
Normally blooming in May in Calgary, depending on the season, it may bloom as early as late April or into June.
Once established, trumpet gentian is long-lived, though may need dividing if it shows signs of crowding or if its flowers diminish over time.
To divide this plant, simply dig up the clump, look for the natural divisions among the basal rosettes, and either pry apart with your thumbs or, if it is a solid mass, use a sharp spade or transplant knife to get two to four new clumps. Immediately replant or pot up. If you prefer not to disturb the original clump, it is easy to take cuttings from the sides, as it naturally forms stolons either at the surface or just below soil level. Pot up divisions or cuttings in a freely draining potting mix until they are well rooted.
Seed may also be collected and surface sown in pots in the fall, with just a bit of compost as a top dressing. Just leave them outside all winter, perhaps in a cold frame.
As they need stratification and absence of light to germinate, cover the pots with newspaper. In spring, you should be rewarded with tiny seedlings that can be potted up and kept in light shade for the season, then returned to the cold frame for another winter.
By the second year, they should be large enough to be planted in your garden or given away as special gifts. It may take some additional years to have seedlings mature enough to flower, so patience is definitely a virtue.
Trumpet gentians are a welcome sight for bees and butterflies that pollinate them. Nothing much bugs them, though slugs may be an issue in a damp summer. As a bonus, they are deer and rabbit resistant.
Versatile in alpine gardens, rock gardens and border edges alike, trumpet gentian should be placed with other plants requiring the same moisture-retentive, slightly acidic soil.
Complement and accentuate the true blue of the trumpet gentian with equally early flowering yellow globe flower (Trollius chinensis) or cowslip (Primula veris).
Throw in some white with snowdrop anemone (Anemone sylvestris) or mountain sandwort (Arenaria montana). Or perhaps for a cooler feel, match trumpet gentian with rock jasmine (Androsace chamaejasme) and mossy saxifrage (Saxifraga hypnoides). But really, the possibilities are endless.
While the trumpet gentian is a bit of a challenge for new and experienced gardeners alike, the reward is a truly lovely and hardy plant with those magnificent and eye-catching blooms. And what Calgary gardener doesn’t love a challenge?