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A picture of a St John’s Wort

St John’s Wort

Hypericum perforatum

Also known as

Perforate St John's Wort, Cammock, Common St John's Wort, Devil Chaser, Devil's Flight, Devil's Scourge, God's Wonder Plant, Herb John, Human Blood, Klamath Weed, Penny John, Rosin Rose, St Columba's Flower, St. John's Wort, Tiptonweed, Goatweed, Racecourseweed

Full Sun
Moderate care
Moderate watering
Frost Hardy

H6

RHS hardiness

-20°C

Minimum temperature

Expected size

Height
Spread

2.5m

Max

1.5m

1m

Min

1m

3 years to reach maturity

Flowering

  • spring
  • summer
  • autumn
  • winter

This plant has a mild fragrance

More images of St John’s Wort

A photo of St John’s Wort
A photo of St John’s Wort
A photo of St John’s Wort
A photo of St John’s Wort
A photo of St John’s Wort

St John’s Wort Overview

A flowering plant and a medicinal herb. A traditional flowering plant that is harvested on St John's Day, 24th June. The genus name 'Hypericum' is derived from the Greek words 'hyper' and 'eikon', in reference to the tradition of hanging plants over religious icons in the home during St John's Day, to ward off evil.

Common problems with St John’s Wort

Problem free

How to harvest St John’s Wort

Not usually harvested, unless for medicine. Pick as needed.

How to propagate St John’s Wort

Seed

Plant seeds in potting soil covered in a light layer of soil. Mist your seeds lightly and be careful not to over-water.

Division

Carefully take divisions when plant is mature with full developed rhizome roots.

Cuttings

Take softwood cuttings during growing season.

Special features of St John’s Wort

Attracts useful insects

Bumblebees, Syrphid flies and beetles may feed on the pollen although they are less effective at pollination. Wasps and butterflies seeking for nectar which the flowers don't produce.

Other uses of St John’s Wort

Found in grassland. Medicinal use.

Medicinal

Medicinal herb with antidepressant activity and anti-inflammatory properties as an arachidonate 5-lipoxygenase inhibitor and COX-1 inhibitor.

Ornamental

Often grown as a garden specimen in borders.

Plants for Long Grass Areas

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