Does it need full sun?

It thrives in full sun but appreciates a little afternoon shade in hotter climates.

Trim back the stems in early spring to encourage bushy growth.

Plant guide

Slender St. John's Wort.

Hypericum pulchrum

Pronounced hy-PEER-ih-kum PULL-krum

Also known as Elegant St. John's Wort, Slender St John's-wort, slender St. John's-wort

This lovely perennial is a charming addition to heathlands and open woodlands. It produces delicate, golden yellow flowers with a distinct reddish tint on the buds. You'll find it thrives best in well drained, acidic soils.

At a glance

Care level: Moderate
Plant type: Perennial
Light: Partial shade to full sun
Indoor light: Bright indirect
Water: Every 5 to 10 days
Mature size: 60 cm
Growth rate: Medium
Hardiness: USDA 6 to 9
Bloom time: Mid to late summer

Care

Keep the soil consistently moist but never waterlogged to mimic its natural habitat. Watch for yellowing leaves which often signal poor drainage or root issues. It prefers a spot with plenty of airflow to stay healthy.

Watering: Water when the top inch of soil feels dry to the touch.
Feeding: Apply a balanced liquid fertilizer during the active growing season.
Pruning: Trim back dead stems in late winter to encourage fresh spring growth.
Repotting: Repot only when the roots have clearly filled the current container.
Soil: Well drained acidic soil
Soil pH: Acidic
Temperature: -15 to 30°C
Humidity: 40 to 70%
Drought tolerance: Moderate
Lifespan: Perennial, typically 5 to 10 years
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of the drainage holes
Stunted growth despite regular care

Safety

People: The plant contains hypericin, which can cause skin irritation and sensitivity to sunlight upon contact or ingestion.
Pets: This plant is considered toxic to cats and dogs if ingested.
Children: Keep this plant away from small children as ingestion of any part can lead to digestive upset and skin sensitivity.
Contact allergens: The sap may cause mild skin irritation in sensitive individuals.
Airborne allergens: There are no notable respiratory allergens associated with this plant.
Edibility: This plant is not considered edible and may cause photosensitivity if ingested.

How to identify it

Small golden yellow flowers
Reddish tinged flower buds
Opposite stem clasping leaves
Slender upright branching stems

Height: 0.3 to 0.6m
Spread: 0.3 to 0.5m
Leaves: green, semi-evergreen
Flowers: yellow, 1 to 2cm
Fruit: brown, Autumn

Problems to watch for

Rust · Fungal spots may appear on leaves during periods of high humidity.

By symptom

Plant problems by symptom

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Growing it

Propagation: seed, cuttings
When to plant: spring, autumn
Overwintering: Mulch the base to protect roots from extreme cold. Cut back dead stems in late winter.
In containers: It grows well in containers at least 30 centimeters wide with excellent drainage.

Semi-ripe cuttings

Take 10 centimeter cuttings in late summer.
Remove lower leaves and dip the base in rooting hormone.
Place in a pot with sandy compost and keep in a cold frame.

Group this plant with other acid loving species to ensure consistent soil conditions.

Grows well with

Heather · They share similar requirements for acidic, well drained soil.
Bell Heather · This plant creates a naturalistic heathland aesthetic alongside the St. John's wort.

Similar species

Common St. John's Wort · It is a larger, more aggressive relative often used for medicinal purposes.

Science

Family: Hypericaceae
Genus: Hypericum
Order: Malpighiales
Class: Magnoliopsida
Native range: Western and Central Europe
Conservation: This plant is common in its native range and is not currently of conservation concern.

It is well adapted to nutrient poor, acidic soils found in open woodlands and heathlands.

Value to wildlife: nectar source
Pollinators: bees
Uses: rock gardens, heathland planting, wildlife gardens

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 3/9
Light: 6/9
Temperature: 5/9
Moisture: 4/9
Nutrients: 2/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need full sun?: It thrives in full sun but appreciates a little afternoon shade in hotter climates.
How do I prune it?: Trim back the stems in early spring to encourage bushy growth.

Where the name comes from

The genus name Hypericum comes from Greek words meaning over an apparition, while the species name pulchrum is Latin for beautiful.

Good to know

It is commonly known as the beautiful St. John's wort.
The plant prefers acidic soils and is often found on heaths.
Its stems are slender and often have a reddish hue.

Also in

Plants toxic to cats and dogs

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This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.