Naturally found in mountainous regions, the gentian is a hardy perennial plant boasting stunning trumpet or star-shaped flowers in vibrant colours. Whether creeping or upright, it always makes a striking addition to a cool rockery! From the blue gentian to the yellow gentian (Gentiana lutea), valued for its medicinal properties and liquor production, this highly ornamental alpine plant can be propagated through various techniques: sowing, root division or stem cuttings. If you're inspired to grow it in your garden, explore our tutorial to learn all about propagating gentians!
(photo peganum - Flickr)
Propagating Gentian by Seed
When to Sow Gentian Seeds?
Sow gentian seeds in autumn under a cold frame. It's best to use fresh gentian seeds as older seeds germinate more slowly and irregularly.
How to Sow Gentian?
Required Materials:
- mini greenhouse (or perforated tray)
- seed compost
- coarse sand or clay pebbles
- gentian seeds
- spray bottle
Sowing Gentian:
To initiate germination, seeds require a period of stratification where they're kept in cold, moist conditions. These winter-like conditions soften the seed coat, promote gas exchange and thus break dormancy. There are two options: place seeds in a plastic bag in the fridge for two months then sow in trays in early spring, or sow in autumn and place the tray outdoors until seeds germinate.
- Line your mini greenhouse with a drainage layer (2cm of sand or pebbles) then cover with compost;
- Moisten and lightly firm;
- Evenly scatter seeds on the surface;
- Dust a very fine layer of compost over seeds to barely cover them;
- Water gently using a spray bottle;
- Cover with the lid (plastic bag or glass pane);
- Keep the growing medium moist.
For natural stratification, place the tray outdoors (temperature between 0 and -5°C) in darkness. Gentians grow rather slowly, with seeds typically germinating within three months. Once seedlings appear, move your tray to a warmer spot not exceeding 18°C, such as a greenhouse or conservatory. Monitor growth and remove the cover occasionally to ventilate and prevent disease. Thin seedlings if needed and transplant into individual pots when large enough to handle. Plant out the following spring, taking care not to damage roots.
Propagating Gentian by Division
When to Divide Gentian?
Divide gentians in early spring for autumn-flowering species or early autumn for spring/summer bloomers. Choose damp weather for easier rootball extraction. This simple method involves separating dense clumps to rejuvenate plants, stimulate new root growth and maintain floriferousness. Use this technique every three years, mainly for mat-forming species like the Alpine Gentian or Spring Gentian, both producing blue flowers. Rosette-forming species like yellow-flowered Gentiana lutea cannot be divided.
How to Divide Gentian?
Required Materials:
Dividing Gentian:
- Select a vigorous plant.
- Loosen soil widely around the rootball using a fork or spade.
- Insert tool vertically around the plant to form a circle.
- Lever the handle to lift the rootball and dig up without damaging roots.
- Divide the clump into two or three sections using a spade or sharp knife.
- Replant divisions immediately in prepared, compost-enriched, well-drained soil.
- Firm gently and water thoroughly.
- Mulch around plants to retain soil moisture.
- Continue regular watering, especially during hot spells.
Propagating Gentian by Cuttings
When to Take Gentian Cuttings?
This technique is best in late spring for certain species, such as Gentiana verna, Gentiana scabra or Gentiana sino-ornata.
How to Take Gentian Cuttings?
Required Materials:
- gravel
- sand
- garden soil enriched with peat or humus
- clay pebbles
- secateurs or knife
- rooting hormone
- pencil
- pot
- cloche, bottle or plastic bag
- spray bottle
Taking Gentian Cuttings:
- Prepare cutting compost by mixing gravel, garden soil and sand.
- Fill pot with clay pebbles (2-3cm) then add compost and moisten.
- Take 7-10cm non-flowering shoots, cutting below a node. Alternatively, select creeping stems that have already formed root initials.
- Remove lower leaves, leaving a rosette at the tip.
- Dip cuttings in rooting hormone.
- Make holes in compost and insert cuttings.
- Water without wetting leaves.
- Keep compost consistently moist.
- Cover with a cloche (this is a closed cutting system) and place in cool shade.
Multiple cuttings can share one pot. For this, use a 20-30cm diameter pot, spacing cuttings apart near the rim. Remove the cloche every 2-3 days to prevent excessive condensation rotting cuttings. Plant out the following spring.
Choose healthy, non-flowering stems for cuttings. Here Gentiana sino-ornata (photo Carstor -Wikimedia)
Further Reading
⇒ All about Gentians: planting, growing and care
⇒ Discover our guide to choosing a gentian
⇒ Learn all steps for sowing in trays
⇒ Everything about taking cuttings: techniques and advice and rooting hormones: a cutting's best friend
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