St. John's Wort, Common St. Johnswort
Hypericum perforatum

Family: Hypericaceae

What it is like

Hypericum perforatum is a PERENNIAL growing to 0.9 m (3ft) by 0.6 m (2ft in). See above for USDA hardiness. It is hardy to UK zone 3. It is in flower from May to August, and the seeds ripen from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.9

Where it is found

Open woods, hedgebanks and grassland, in dry sunny places, usually on calcareous soils.

Europe, including Britain, south and east to N. Africa, the Azores, Madeira and W. Asia.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

The herb and the fruit are sometimes used as a tea substitute. The flowers can be used in making mead.

Tea: the various herb teas that can be used in place of tea, plus the genuine article.

Medicine

Rating: 4

St. John's wort has a long history of herbal use. It fell out of favour in the nineteenth century but recent research has brought it back to prominence as an extremely valuable remedy for nervous problems. In clinical trials about 67% of patients with mild to moderate depression improved when taking this plant. The flowers and leaves are analgesic, antiseptic, antispasmodic, aromatic, astringent, cholagogue, digestive, diuretic, expectorant, nervine, resolvent, sedative, stimulant, vermifuge and vulnerary. The herb is used in treating a wide range of disorders, including pulmonary complaints, bladder problems, diarrhoea and nervous depression. It is also very effectual in treating overnight incontinence of urine in children. Externally, it is used in poultices to dispel herd tumours, caked breasts, bruising etc. The flowering shoots are harvested in early summer and dried for later use. Use the plant with caution and do not prescribe it for patients with chronic depression. The plant was used to procure an abortion by some native North Americans, so it is best not used by pregnant women. See also the notes above on toxicity. A tea or tincture of the fresh flowers is a popular treatment for external ulcers, burns, wounds (especially those with severed nerve tissue), sores, bruises, cramps etc. An infusion of the flowers in olive oil is applied externally to wounds, sores, ulcers, swellings, rheumatism etc. It is also valued in the treatment of sunburn and as a cosmetic preparation to the skin. The plant contains many biologically active compounds including rutin, pectin, choline, sitosterol, hypericin and pseudohypericin. These last two compounds have been shown to have potent anti-retroviral activity without serious side effects and they are being researched in the treatment of AIDS. A homeopathic remedy is made from the fresh whole flowering plant. It is used in the treatment of injuries, bites, stings etc and is said to be the first remedy to consider when nerve-rich areas such as the spine, eyes, fingers etc are injured.

Analgesic: Relieves pain.

Antidepressant: Used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder.

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.

Aromatic: Having an agreeable odour and stimulant qualities.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Cholagogue: Increases the flow of bile and its discharge from the body.

Digestive: Aids digestion.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Expectorant: Clears phlegm from the chest by inducing coughing.

Homeopathy: A plant used in homeopathic treatments.

Nervine: Stimulates and calms the nerves.

Resolvent: Breaks down tumors. This might be placed under antitumor.

Sedative: Gently calms, reducing nervousness, distress and irritation.

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Vermifuge: Expels and kills internal parasites.

Vulnerary: Promotes the healing of wounds.

Other

Rating: 2

Yellow, gold and brown dyes are obtained from the flowers and leaves. A red is obtained from the flowers after acidification. A red dye is obtained from the whole plant when infused in oil or alcohol. A yellow is obtained when it is infused in water. The plant is said to contain good quantities of tannin, though exact figures are not available.

Dye: Plants that provide dyes.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Scented Plants: Plants noted for their scent

How it is grown

Easily grown in any reasonably good well-drained but moisture retentive soil. Succeeds in dry soils. Plants grow well in sun or semi-shade but they flower better when in a sunny position. St. John's wort is often found as a weed in the garden. It grows well in the summer meadow and is a useful plant for attracting insects. The whole plant, especially when in bloom, gives off a most unpleasant smell when handled. Hypericum perforatum is apparently an allotetraploid that would appear to have arisen from a cross between two diploid taxa, viz. H. maculatum subsp. maculatum (Europe to western Siberia) and H. attenuatum (western Siberia to China). In garden design, as well as the above-ground architecture of a plant, root structure considerations help in choosing plants that work together for their optimal soil requirements including nutrients and water. The root pattern is rhizomatous with underground stems sending roots and shoots along their length .

Propagating it: Seed - sow in a greenhouse as soon as it is ripe in the autumn or in the spring. It normally germinates in 1 - 3 months at 10°c. Prick out the seedlings into individual pots when they are large enough to handle and plant them out into their permanent positions in the summer. Division in spring or autumn. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; Meadow; Hedgerow;

Habit: Perennial

Hardiness: 3-7

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Skin contact with the sap, or ingestion of the plant, can cause photosensitivity in some people. Common side-effects are gastointestinal disturbances, allergic reactions & fatigue. If used with drugs classed as serotonin reuptake inhibitors (fluoxetine:Prozac, paroxetine:Paxil) symptoms of serotonin syndrome may occur: mental confusion, hallucinations, agitation, headache, coma, shivering, sweating, fever, hypertension, tachycardia, nausea, diarrheoa, tremors. St John's wort can reduce the effectiveness of prescription medicine inc: contraceptive pill, antidepressants, immune suppressants, HIV medications, warfarin, digoxin .

Its other names

Local names

Synonyms

Hypericum deidesheimense, Hypericum vulgare, Hypericum lineolatum, Hypericum mixtum.