St. John’s wort (Hypericum perforatum)
In medieval Europe St. John’s wort was considered to have powerful magical properties, that enabled to repel evil spirits. In modern day herbal medicine it is used as an antidepressant. It has also anti-inflammatory and pain relief effects. St. John’s wort opens its sunny flowers just in time for the start of summer. It is native to Europe and grows wild throughout much of the world. It can be found in meadows, on banks and by the roadside and prefers a sunny position. The flowery tips are harvested in midsummer.
In nature St. John's wort is one of the pioneer plants that spread where nothing else grows. Nevertheless, the plant also looks good in the garden. If you give it a sunny spot on loose soil, it grows upright to a height of 50 cm and its golden yellow flowers shine from the end of June to the beginning of September. The egg-shaped leaves sit on two-edged, pithy stems.
Where does the name come from?
In June the sun is at its highest and the days are the longest. Our pre-Christian ancestors celebrated the summer solstice on June 21st as one of the most important festivals of the year with bonfires and all kinds of rituals. They wove herb bouquets and wreaths, which they carried around the fire while dancing and then threw into the flames. This was supposed to ensure protection, health and prosperity. And since these pagan customs could not be eradicated, the church re-dedicated the occasion by making June 24th the day of Saint John the Baptist, so that all festivities could be dedicated to him. Since one of the most important wild herbs blooms around the solstice, it was given the name St. John's wort.
Native perennial and medicinal herb
St. John's wort (Hypericum perforatum) has a centuries-long tradition as a medicinal herb. It sees the beginning of flowering as a mission, because it brings sunshine, warmth and good cheer to depressed minds. It is used as a mood enhancer and to calm states of restlessness and stress. Modern pharmacy has long been processing St. John's wort into finished products, but it was already used in folk medicine, brewing the herb as a tea.
Alcohol or oil makes a cold extract. The latter in particular is still in use today, because the red oil is easy to make and has an anti-inflammatory and anti-viral effect, heals burns, sunburn and abrasions on the skin, relieves pain from muscle tension, lumbago and rheumatism.
A complex mixture of substances is responsible for the antidepressant effect (red-coloured hypericin and hyperforin, flavonoids hyperoside and rutoside as well as tannins and essential oils).
How to recognise Hypericum Perforatum
Against the light, you can see in the leaves and yellow petals, translucent dots, which are responsible for the botanical species name perforatum. These are oil glands that release red-coloured juice when rubbed between the fingers.
Make your own red oil
If you have St. John's wort in your garden, you can easily make your own red oil. When it is in full bloom, cut off the flowering tops. Slightly crush the material in a mortar. Put it in jar until it is about half full. Then pour high-quality organic oil over it (we use extra-virgin olive oil) until all parts of the plant are covered. Place the jar covered with a muslin and keep in a sunny, warm place for four to six weeks. Shake the mixture once a day. After a while, the oil will turn red and you can finally filter the herb through a cloth, pour into a clean jar, label and store in a dark place.
Ornamental St. John’s wort
Given the popularity of true St. John's wort, some people tend to overlook the fact that there are a number of other, much less well-known St. John's wort’s with very similar flowers, but without medicinal properties. The genus Hypericum includes around 400 species. All are valuable insect food plants.
Interesting for gardeners are the following:
Dwarf St. John's wort (H. polyphyllum 'Grandiflorum) is recommended for dry stone walls, rock gardens and boxes. The 15-20 cm small subshrub thrives in full sun on humus- and nutrient-poor, permeable soil.
As a vigorous ground cover, low St. John's wort (H. calycinum), on the other hand, solves many garden problems. It adds greenery to sunny and lightly shaded areas, tolerates root pressure, heat and drought. The subshrub quickly forms dense carpets and flowers from July until September.
The same applies to lemon St. John's wort (H. hircinum). However, it forms attractive, rounded shrubs 50-120 cm high.
St. John's wort (H. androsaemum), also known as man's blood, is versatile in the garden. This shrub, which is around 1 m tall and wide, cuts a fine figure as a solitary plant, in a small group or as a hedge, throughout the entire season.
The most well-known shrub among St. John's wort’s is the 'Hidcote' variety, sometimes classified as a large-flowered St. John's wort (H. patulum). The shrub grows to a stately 80-150 cm high, bears evergreen, dark, bluish underside foliage on arched shoots. It is frost-hardy and heat-tolerant and has no special soil requirements. It is no wonder that Hidcote' can also often be admired in public green spaces.
Caution: In Ireland St. John’s wort products for internal use are only accessible through a qualified herbalist or prescription by a doctor.