Gentian: planting, care & hardiness of Gentiana
When thinking of gentians, many immediately picture the intensely blue flowers in their natural alpine environment. But the gentian genus contains many species, and some varieties will happily grow in the garden.
Some gentians can be grown both in the garden and in pots. This article provides an overview of the gentian genus (Gentiana) and its characteristics. Read our other article for detailed information on the specific gentian species and varieties.
Contents
Gentian: flowers, properties and origin
The Gentiana genus belongs to the Gentianaceae family and contains over 300 different species, 35 of which are native to Central Europe. The gentian species are found in the northern hemisphere, predominantly growing in temperate mountain regions. Gentians can be perennial, annual, or biennial. All of the species are herbaceous plants that grow mostly upright and have leaves with smooth margins. The trumpet-shaped flowers can be single blooms or in inflorescences. While they are best known for their blue wildflowers, gentian flower colours range from violet to yellow and white. The height of the plants varies greatly depending on the species, as some are low-growing and others are tall-growing, so the size of gentian plants can range from 5 cm to 150 cm. While the attractive hybrid varieties are generally grown as ornamental plants, the great yellow gentian (Gentiana lutea) is used to make schnapps. Here, the bitter-tasting gentian roots are used. Gentiana lutea is also used medicinally because it stimulates the appetite.
The plant is pollinated by insects that feast on the gentian flower’s nectar and pollen. Some species and insects have a symbiotic relationship in which each is dependent on the other. There are a number of native wild gentian species in the UK, including the protected and endemic early gentian, the rare and minute spring gentian (Gentiana verna) and the more common Autumn gentian (Gentiana amarella).
When is the gentian in bloom?
The gentian’s flowering season varies depending on the species. The stemless gentians (Gentiana acaulis), which are native to Central Europe, first show their deep blue flowers in spring and can even bloom again in autumn. Other species, like the autumn bell flower (Gentiana pneumonanthe), which is native to the UK, bloom in summer, between July and August. Meanwhile, many Asian species, such as Gentiana scabra, will flower in autumn.
Where are gentians found in the wild?
Just like the famous edelweiss (Leontopodium), many gentian species are mountain shrubs that thrive in high mountain environments such as the Alps, Pyrenees, or Andes. Grazing animals largely avoid the bitter-tasting plant, which is why some species flourish on mountain pastures. In general, the gentian flower prefers stony and rocky environments with moist substrates and partial shade. Some species can also be found in forests.
Planting gentians: location and method
It is important to consider the requirements and natural habitats of individual species when choosing a location for your gentian plant. A bright semi-shady spot is ideal for all varieties of these alpine plants. Gentians like a stony, loamy, humus-rich soil that has good drainage but also retains water well. Other requirements differ so greatly between species that they must be considered separately. Unsuitable garden soils can be improved. Work our Plantura Organic All Purpose Compost into deficient substrates to improve the structure and add more organic matter. Our organic compost with its long-lasting, loose structure provides the soil with the necessary permeability required by the gentian plant while also retaining enough water.
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Tip: Even though grazing animals tend to avoid gentian flowers, snails and slugs will munch on them. Find out how to protect your plants against slugs in our feature article.
Gentians are best planted in spring and autumn. As different species grow to different sizes, the exact timing and plant spacing must be tailored to each one.
Planting gentians in pots: If you want to grow your gentian in a pot, first research the species’ requirements. Depending on the plant’s soil preference, simply use a high-quality potting soil, such as our Plantura Organic All Purpose Compost, or mix in some volcanic rock dust into the soil. Use a fairly large pot with a drainage hole. Add a drainage layer of pebbles or clay shards to the bottom of the pot to prevent any waterlogging. After planting, place the pot in a semi-shady, cool and wind-protected spot. Keep an eye on your potted gentian, especially when watering and during the winter. The following species are ideal for growing in pots:
- Stemless gentian (Gentiana acaulis)
- Spring gentian (Gentiana verna)
- Showy Chinese gentian (Gentiana sino-ornata)
- Crested gentian (Gentiana septemfida)
Gentiana plant care
Gentians are modest and hardly little plants. In fact, they demand little more than the right location, occasional watering and some fertilising each year.
Gentians growing in the bed like fresh, moist soil and, depending on the weather, regular waterings. Potted gentian flowers require more frequent watering because a pot rarely holds enough soil to store the necessary amount of water. When the soil’s surface has dried out, water the plant again.
When growing gentian plants in pots, the nutritional content of the soil generally meets the plant’s needs for the upcoming season. Feed gentians growing in the flowerbed with a slow-release fertiliser such as our Plantura All Purpose Plant Food at least once in spring and again in summer for the faster growing species. Our fertiliser not only nourishes the plant, but it also replenishes the soil as a whole. It lasts for three months and provides essential nutrients to the gentian during that time.
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Taller growing varieties like the great yellow gentian or the willow gentian can be pruned, but it is not required. Prune in spring before the new shoots appear.
Are gentians hardy?
Generally speaking, gentian plants are hardy, even in the harshest of winters in the UK, but some species will tolerate lower temperatures than others. To be on the safe side, put down a layer of mulch to protect them from deep frosts. This layer helps the gentian by preserving soil warmth and moisture. Frost protection is necessary for potted gentians during the winter. Wrap the pot with some fleece and place it on a block of wood to prevent the soil from freezing.
Propagating gentians
Both division and sowing are suitable methods of propagation for the gentian. However, bear in mind that dividing works only with perennial Gentiana plants such as:
- Stemless gentian (Gentiana acaulis)
- Willow gentian (Gentiana asclepiadea)
- Showy Chinese gentian (Gentiana sino-ornata)
To propagate by division: dig up the plants together with the roots and carefully divide into two or more parts, making sure each part has a few roots. For rhizome forming species such as Gentiana acaulis, separate single shoots already bearing their own roots as well. Then replant in a suitable location straightaway.
Sowing gentians is somewhat more complicated, but seed propagation is a better method for gentian species with sensitive roots such as:
- Great yellow gentian (Gentiana lutea)
- Purple-flowered gentian (Gentiana purpurea)
After flowering, harvest the ripe seed capsules from the plant and extract the Gentiana seeds. Store in a cool, dry place until ready to sow. In autumn, fill seed trays with a growing medium, such as our Plantura Organic Herb & Seedling Compost, and scatter seeds on them. Our soil is peat free and contains few nutrients to encourage the young plants to develop roots.
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Cover the seeds lightly with soil and keep them moist until they germinate. As the gentian is a tough little mountain plant, cold weather in winter will not get in the way of germination but rather benefit the process. Once the gentian seeds have germinated in spring, prick out the young seedlings and plant in a suitable location.
Medicinal uses of Gentiana plants
The main medicinal value of this plant lies in the roots, which contain bitter substances that stimulate appetite. Gentian root is primarily consumed as an herbal tea, often mixed with other medicinal plants. It can also be taken as a liquid extract to help with digestive issues. In traditional medicine, gentian roots are used to treat spleen and liver ailments, stomach aches and digestive issues. Gentian schnapps is also popular.
Is gentian poisonous?
Gentian is not poisonous and poses no danger to humans or animals. Most animals do not eat it because of its bitter taste.
Aside from gentian flowers, many other plants thrive in mountainous or arid environments and will feel right at home in rock gardens. Learn how to make your own beautiful rock garden.
