St John's wort
Hypericum montanum · Hypericaceae
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around st john's wort and prepare for winter.
ID card
- Foliage
- Deciduous to semi-evergreen depending on climate
- Flowering
- June to August, golden-yellow flowers
- Adult size
- 0.6 to 1.5 m in height
- Hardiness
- Very hardy down to -20 °C
- Growth
- Moderate
- Origin
- Mountains of central and southern Europe
- Exposure
- Full sun to partial shade
- Soil type
- Well-drained, chalky or slightly acidic
Care
Watering
Mountain St. John's wort appreciates moist but well-drained soil. Water regularly during active growth periods, especially in summer if drought persists. Once established, it will tolerate dry spells better. Avoid excess moisture in winter.
Exposure and light
Plant this in full sun for optimal flowering, or accept light partial shade. At least 6 hours of direct daily sunlight is recommended. Too shady a location will reduce flowering and make the plant leggy.
Pruning and maintenance
Lightly cut back in late winter to maintain a compact, bushy shape. Remove dead or diseased branches in spring. Gentle pruning after flowering stimulates branching and plant density.
Fertilizing
Mountain St. John's wort is undemanding. A moderate application of balanced fertilizer in spring is sufficient. Avoid excess nitrogen, which would encourage lush foliage at the expense of flowering.
Soil preparation
Prepare well-drained soil, ideally with a mix of potting soil and coarse sand if your soil is heavy. This plant tolerates chalky and poor soils. Adding moderate organic matter at planting helps establishment.
Diseases and pests
Mountain St. John's wort is generally robust and not very prone to pests. In case of excessive moisture, watch for root rot. Good air circulation and optimal drainage reduce these risks.
Did you know?
The Hypericum genus has been known since antiquity: ancient Greeks and Romans already used St. John's wort in rituals and traditional medicine. Its Latin name "Hypericum" is thought to derive from the Greek "hyper" (above) and "eikon" (image), because in the Middle Ages it was hung above religious icons, being considered a protective plant.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- Rose of sharonHypericum calycinum
- Tall tutsanHypericum inodorum
- Egyptian Saint John's WortHypericum aegypticum
- Hooker's St. JohnswortHypericum hookerianum
- Moser's St. John's wortHypericum moserianum
- Hypericum dummeriHypericum dummeri
Tips generated and checked by Viridia — adapt them to your local climate.