Moser's St. John's wort
Hypericum moserianum · Hypericaceae
⚠️ Feuilles et fleurs : photosensibilité et dermatite de contact par manipulation, troubles digestifs par ingestion chez animaux et enfants.
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around moser's st. john's wort and prepare for winter.
ID card
- Foliage
- Deciduous to semi-persistent depending on climate
- Flowering
- June to August, golden yellow flowers with red stamens
- Mature size
- 60 cm tall × 60 to 80 cm wide
- Growth
- Fast, densifying
- Hardiness
- Down to -15°C
- Optimal exposure
- Full sun
- Water needs
- Moderate, undemanding
- Origin
- Horticultural hybrid (China)
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Hypericum moserianum stays denser with light pruning after flowering. It tolerates poor soils but appreciates moderate moisture during summer.
The common mistake
Avoid leaving it untrimmed, as this gives a plant that's airy in the center and flowers less.
The pro's trick
After flowering, shorten the spent branches to encourage lower branching.
Seasonal watch
In very dry summers, light mulching limits premature leaf yellowing.
Care
Exposure
Plant your St. John's wort in full sun for generous flowering and vibrant colors. It tolerates light shade but will flower less abundantly. Protect it from strong winds that can damage its delicate stems.
Watering
Water regularly after planting and during prolonged dry periods. Once established, this St. John's wort adapts well to dry conditions and needs only moderate watering. Avoid standing water that promotes rot.
Soil
St. John's wort prefers well-drained soil, even poor or rocky soil. It tolerates slightly acidic to neutral soils. Enrich the soil with compost at planting time, but avoid excessive fertility that would harm flowering.
Pruning and maintenance
Prune in late winter or early spring to maintain a compact, dense shape. Remove dead wood and tangled branches. Light pruning after summer flowering encourages a second flush of flowers in autumn.
Fertilizer
An annual application of compost or slow-release fertilizer in spring is sufficient. This St. John's wort is undemanding and reacts poorly to excess nitrogen, which promotes foliage at the expense of flowers. Avoid mineral overloading.
Diseases and pests
St. John's wort is generally hardy. Watch for powdery mildew in persistent humidity: ensure good air circulation and avoid overhead watering. Scale insects may occasionally appear but are rare on healthy plants in good light.
Did you know?
The Hypericum genus, to which this St. John's wort belongs, has been associated since antiquity with protective and therapeutic properties. Its name evokes the time of St. John's Day, when European farmers would harvest St. John's wort flowers to make decoctions. Hypericum moserianum, more modest, remains an excellent ornamental plant for busy gardeners seeking color without hassle.
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
- Kalm's St. John's-wortHypericum kalmianum
- Hypericum dummeriHypericum dummeri
Tips generated and checked by Viridia — adapt them to your local climate.