Iperico: St. John’s wort

Hypericum Perforatum commonly known as St. John’s wort is a herbaceous and perennial plant belonging to the Hypericaceae family native to Europe, central China, northern Africa and the western Himalian source. It also has many branches, yellow flowers and grows mainly in fields, uncultivated land, pastures and even on railways. The Hypericum can reach about 180 centimeters in height and develops well from June to August both in full sun and in dim conditions.

The cultivation of Hypericum

Easily cultivable in medium humidity and well-drained soils, St. John’s Wort however prefers sandy or gravel-enriched ones and with a pH between 5.5 and 7. It also tolerates a little drought once established. Every single plant can produce up to 100,000 seeds per year. A good diet based on suitable fertilizers and available in nurseries and on the best online stores in charge of selling will tend to increase the flowers produced by the shrub. The ideal is to administer it (of the slow release type) in spring and work it a little in the ground. Thereafter, use a well-balanced liquid fertilizer monthly during the growing season and alternatively apply well-decomposed manure.

Diseases and treatments

Hypericum is a plant that generally presents few problems in terms of diseases and parasitic invasions, although some aphids, if in excess, can affect its longevity, undermining its native characteristics. If you notice brownish bumps on the stems especially where the twigs join or near the buds, the condition could be caused by the presence of scale insects. These insects suck the sap of the plant and expel the honeydew which can lead to the growth of sooty mold. Scraping them with a cotton swab dipped in alcohol proves to be very effective in these situations. If the problem is extensive, it is advisable to remove and dispose of all infected branches and use an insecticide spray, avoiding it when the shrub is in flower as it could harm the pollinating insects.


Since ancient times, St. John’s Wort plants have been used as herbal treatments for a variety of skin-related problems (wounds and burns) and internally for anxiety, depression, and insomnia. The genus name derives from the Greek words hyper meaning above and eikon image, referring to the practice of hanging flowers of this genus above portraits or windows. Growing Hypericum in a home garden or on a terrace means creating a context typical of the woodland, not to mention that these specimens are also suitable as cut flowers to decorate domestic interiors or exteriors for parties and various events.

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