Description of Hypericum perforatum (Perforate St John's-wort)

Hypericum perforatum is perforate St John's-wort. You’ll also see it called common St John’s-wort. It’s not a true bog plant, but it can work on the drier edge of a bog garden where soil stays lightly moist rather than wet.

Appearance

It forms upright stems with narrow leaves. In summer it produces yellow flowers with lots of stamens. Height is often 40 to 80cm, depending on the site. It can self-seed in open ground.

Care Guide

It prefers sun and soil that drains. If you sit it in constant saturation, it often looks unhappy and short-lived.

• Sun: Full sun is best.
• Soil: Moist but free-draining soil. Avoid stagnant, waterlogged compost.
• Water: Water in dry spells while it establishes, then it is fairly tough.
• Cut back: Trim back in spring to keep it compact.
• Control: Deadhead or thin seedlings if it self-seeds too freely.

If you want a neater plant, cut it back after the main flowering flush. It often responds with fresh growth.

Suitability for Bog Garden

This suits bog gardens only as a transition plant on the upper edge. Use it where water drains away, such as the top lip of a raised bog or the outer rim of a liner bog.

It is better in nearby damp meadow planting than in the wet centre.

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