Hairy St John's wort
Hypericum hirsutum · Hypericaceae
The gardener's calendar
Ideal time to plant hairy st john's wort: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Hairy St. John's Wort
- Family
- Hypericaceae
- Type
- Perennial herbaceous
- Foliage
- Deciduous
- Flowering
- June to September, yellow flowers
- Adult size
- 16 to 32 inches tall
- Hardiness
- Very hardy (down to -4°F)
- Origin
- Western and central Europe
Care
Watering
Hairy St. John's Wort appreciates moist but well-drained soil, especially during the growing season. Water regularly during summer if there's prolonged drought, but avoid waterlogging which promotes rot. Once established, it tolerates dry periods well.
Exposure
Plant in full sun to partial shade for optimal flowering. St. John's Wort accepts semi-shaded locations, but produces more flowers in full sun. Protect it from strong winds in very exposed areas.
Soil
This herbaceous plant prefers rich, loose, well-drained soil, slightly acidic to neutral. Improve poor soils with compost or organic matter at planting time. Hairy St. John's Wort adapts to many soil types, including slightly chalky soils.
Pruning
In late winter or early spring, cut back stems to 4-6 inches from the ground to encourage dense, bushy growth. Remove faded flowers regularly to stimulate continuous flowering. Prune damaged stems at any time of year.
Fertilizing
An application of well-decomposed compost in spring is usually sufficient. In depleted soil, apply balanced fertilizer at the start of the growing season. Avoid excess nitrogen, which tends to favor foliage at the expense of flowers.
Diseases and pests
Hairy St. John's Wort is generally very robust and seldom subject to diseases. Watch for powdery mildew in humid, stagnant conditions. Good drainage and sufficient air circulation through the foliage prevent most fungal problems.
Did you know?
Hairy St. John's Wort is one of many species in the Hypericum genus, renowned since ancient times for their interesting properties: the name "St. John's Wort" literally means "a thousand holes," alluding to the tiny translucent glands visible on the leaves and petals. In summer, when you crush the flowers, they release a reddish liquid, hence the medieval name "herb of St. John," because flowering coincides with this feast day.
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
- 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.