St. John's Wort (Hypericum) are popular perennials found in many home gardens. We present the ancient medicinal plant and provide tips on cultivation, care and use.
St. John's wort is a well-known garden and medicinal plant. We give you an overview of the properties, requirements and cultural measures for the successful cultivation of St. John's wort.
St. John's wort: origin and properties
In the genus St. John's Wort (Hypericum) there are 500 to 700 species that are distributed worldwide. They are part of the St. John's wort family (Hypericaceae). Several species of St. John's wort are native to our latitudes, the best known is certainly St. John's wort (Hypericum perforatum). In history, St. John's wort has also accompanied Christianity from the beginning. The name derives from John the Baptist, whose blood is said to have flowed into the flowers of St. John's wort after his beheading. If you rub the yellow petals between your fingers, reddish plant sap escapes. Therefore, the St. John's wort is also called St. John's blood in some places. In the past it was also known as the royal crown or hard hay because of its golden-yellow flowers, as the plant quickly becomes lignified and leaves behind hard stalks.
St. John's wort is a perennial herb that, depending on the species, is evergreen or dies above ground in autumn and sprout fresh in spring. The plant is 60 to 80 cm high on average, but there are also low-growing, ground-covering species and significantly larger ones up to 150 cm. St. John's wort usually forms several branched stems that can be round, angular or winged and are green to reddish brown in colour. The opposite, oval to lanceolate blue-green to green leaves of St. John's wort often have many transparent or dark spots. These are oil glands. The golden-yellow, five-pointed petals can also appear perforated, this is particularly noticeable in the speckledSt. John's Wort (Hypericum maculatum).
Bees and other pollinating insects like to visit the golden yellow to light yellow flowers, as they provide food from midsummer to autumn. The flowers also have numerous stamens, which protrude from the center as thin threads and load up their pollen on willing pollinators. The heyday of St. John's wort usually begins around St. John's Day in June and can last until October. After pollination, either greenish-brown, inconspicuous capsule fruits or red, orange, pink or white colored fleshy berries are formed.
Risk of confusion: A plant similar to St. John's wort is the poisonous ragwort (Senecio jacobaea). However, if you take a closer look at the smaller flowers, you will see that they have a completely different structure than St. John's wort and no stamens protrude. They look like daisies - typical for daisy family (Asteraceae). Ragwort leaves are alternate and pinnate.
Grow St. John's wort: location and procedure
St. John's wort has different requirements for its planting site depending on the species, but is generally undemanding and tolerant of different locations. The ideal location for St. John's wort is sunny to semi-shady on humus-rich, well-drained soil. Some species prefer acidic, others calcareous, moist to dry soil. Details on the location requirements of individual St. John's wort species can be found in our variety article.
St. John's wort plants can be purchased in perennial nurseries or you can sow them yourself. These are light and cold germs. This means that the seeds initially need a longer cold period. They should then be covered with little or no soil and given plenty of light to germinate. The seeds can be pre-treated in the refrigerator for six weeks and then sown. For this purpose, the elongated, red-brown seeds are spread on nutrient-poor potting soil, such as our Plantura herb and seed soil. The seeds are lightly pressed and only minimally covered with soil. The seed container is set up in a bright but not sunny location at around 20 °C and the soil in it is always kept moist. After two to three weeks, the first seedlings will appear. Alternatively, sow the seeds outside in the fall and leave them out in the cold. St. John's wort has a high germination rate and therefore some seeds will surely sprout in the following springon. The seedlings can be planted or transplanted after a few weeks.
The best planting time for hardy perennials is in late autumn between October and the end of November. Alternatively, it can be planted in early spring before the leaves sprout in early March. Since the perennials have not yet been able to form roots, they must be watered regularly in the coming summer. In the bed, St. John's herbs can be planted in groups, as a dwarf form for ground cover or as individual shrubs. The planting distance for groups is about 40 cm, six to eight plants are planted per square meter. Low St. John's wort species such as St. John's wort (Hypericum polyphyllum) are used for ground cover and 12 to 15 pieces are planted per square meter. Individual, larger shrubs such as the large-flowered St. John's Wort (Hypericum x patulum) should be spaced 1.5 to 2 meters from other plants. Proceed as follows when planting St. John's wort:
- Loosen the soil at the future location, work in some mature compost if necessary.
- Dig a sufficiently large and deep planting hole.
- Do not place the St. John's wort plant any deeper than before, fill up with excavation and press lightly all around.
- Water vigorously.
St. John's wort in a pot: St. John's wort can be cultivated as a pot plant. The pot volume should hold at least 5 liters. Good water drainage and an approximately 5 cm high drainage layer made of sand, gravel or expanded clay is important. However, the pots should be given an insulating winter protection when overwintering outdoors.
Summary: Plant St. John's Wort
- Sowing: indoors with cold treatment or outdoors in autumn
- Location: sun to partial shade
- Soil: humic and permeable; Depending on the type, acidic or calcareous, moist to dry
- Time: October - end of November or beginning of March
- Planting distance: 40 cm (in groups), 1.5 - 2 m (single), 12 - 15 plants/m2 (ground cover)
Care for St. John's wort: cutting, watering & Co.
St. John's wort is an ornamental and medicinal plant that is easy to care for. Especially in the first year after planting and in dry, hot summers, it should be watered from time to time.
You should not fertilize the perennial too much, because a high supply of nitrogen reduces the content of beneficial substances. OneAnnual application of compost or predominantly organic long-term fertilizer, such as our Plantura organic universal fertilizer, in the spring for sprouting is completely sufficient for St. John's wort.
In addition to pruning when the St. John's wort is harvesting, the perennial is also pruned in spring. In the case of perennial St. John's wort, all dead plant parts are removed before they sprout, and the perennial can then grow fresh. For evergreen plants and shrubs, frostbitten or old and injured shoots are removed in spring.
Propagate St. John's Wort
St. John's Wort can be propagated from seeds and cuttings. In autumn you can win the St. John's wort seeds yourself. To do this, collect the capsules or berries in October and allow them to dry gently at room temperature for a few weeks. The dry seeds are already falling out of the capsules, the berries have to be broken open to obtain the seeds. St. John's wort seeds can be stored in a dry, cool and dark place for several years without the germination capacity suffering.
It is best to cut cuttings from the young, still unwoody shoot tips before flowering in May. These approximately 10 cm long pieces of shoots are defoliated down to the tip and placed in nutrient-poor potting soil half enriched with sand. At around 20 °C, kept light and moist, the first tender roots will form after a few weeks. The cuttings can be planted out in autumn of the same year.
Tip: In the case of perennials that die off each autumn - unlike the shrubs of St. John's wort, which do not die above ground - the rootstock can also be divided. For this purpose, a piece of the eyrie is cut off with a spade in autumn and moved.
Is St. John's wort hardy?
St. John's wort is completely hardy in our latitudes. If you only cut back dead plant parts above ground in the spring, there is additional protection for the perennial. St. John's wort in a pot should receive an insulating winter protection from jute bags, needle branches or fleece.
Harvesting and using St. John's wort
Only St. John's wort is important in pharmacy. When the St. John's wort is in bloom from June, the above-ground parts of the plant are collected. If you harvest St. John's wort early in the morning, then the proportion of positive active ingredients such as hypericin is highest. You can cut off the whole plant or just flowers and individual leaves. After harvestSt. John's wort, it should be used quickly in order to preserve the precious ingredients. You can use it to prepare tinctures or dry leaves and flowers for St. John's wort tea. The plucked blossoms are filled into a bottle together with high-quality vegetable oil and stored in a sunny and warm place for about six weeks. The resulting red St. John's wort oil can be used for several months.
Use of St. John's Wort
Preparations or capsules made from St. John's wort as well as extracts and red St. John's wort oil are used for depressive moods, states of anxiety and nervousness. Applied externally as a care oil, St. John's wort relieves muscle pain and skin irritation, promotes wound healing and has an anti-inflammatory effect. However, the use of St. John's wort should always be discussed with a doctor, as it can cause interactions with certain medications. One of the side effects of St. John's wort is the increased sensitivity to light due to the coloring hypericine. Fair-skinned people should therefore avoid sunbathing when taking St. John's wort.
Is St. John's wort poisonous?
St. John's wort is classified as slightly toxic, mainly because of the photosensitivity of the skin resulting from consumption. White grazing animals such as horses, sheep or goats can suffer from hay fever after excessive consumption of St. John's wort and exposure to sunlight.
Another perennial medicinal plant for your own garden is the dainty speedwell (Veronica). Find out everything about the plant, its needs and its use.