Thesium alpinum
Thesium alpinum · Thesiaceae
The gardener's calendar
Ideal time to plant thesium alpinum: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Thesiaceae
- Type
- Perennial herb
- Flowering
- June to August
- Adult size
- 15 to 40 cm tall
- Foliage
- Deciduous
- Hardiness
- Very hardy (zones 3-8)
- Origin
- Mountains of central and northern Europe
- Soil
- Well-drained, chalky or neutral
Care
Sunlight
Thesium alpinum thrives in full sun or light partial shade. This mountain plant appreciates airy and open situations. Make sure it gets at least 4 to 5 hours of direct light daily for optimal flowering.
Watering
Water moderately during the growing season, making sure not to create waterlogging. This alpine plant tolerates dry periods well once established. In winter, reduce watering to the bare minimum. The soil should remain fresh but never waterlogged.
Soil and drainage
Thesium alpinum requires perfectly drained soil, slightly chalky or neutral. Adding gravel or coarse sand improves drainage and recreates its natural environment. Avoid heavy, compact or overly organic-rich soils.
Pruning and maintenance
This low-growing plant doesn't require severe pruning. Remove dead or dried stems in early spring. You can cut it back lightly after flowering to encourage a more compact and dense clump.
Fertilizer
Thesium alpinum is a frugal plant that needs little nutritional input. A diluted balanced fertilizer, applied once in spring, is more than enough. Avoid excess nitrogen, which would weaken the plant's robustness.
Diseases and pests
This hardy plant is rarely subject to pests and diseases. Make sure to maintain good drainage to prevent any risk of rot. In overly humid conditions, root rot may appear: improve soil aeration in that case.
Did you know?
Thesium alpinum is a singular semi-parasitic plant: its roots are equipped with suckers that allow it to extract nutrients from the roots of neighboring plants. Long ago, alpine populations used it in traditional medicine, particularly for its supposed detoxifying properties. This remarkable adaptation makes it a fascinating spectacle of botanical co-evolution in mountain environments.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
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Tips generated and checked by Viridia — adapt them to your local climate.