Hypericum perforatum, St John's Wort
Lightly scented yellow flowers with tiny black gland dots. Small stalkless, oval, green leaves covered with tiny translucent resin glads that look like small spots. Important medicinal herb.
• Hardiness: H6 (-15 to -20C)
• Type: Semi Evergreen Perennial
• Height: 30-90cm
• Spread: 30cm
• Soil type: Chalk, Clay, Sand, Loam
• pH: Universal pH
• Habit: Upright
• Flowering colour: Yellow
• Flowering time: Summer
• Uses: Medicinal (Read Jekka's Guide to Medicinal Herbs for more information)
• Attracts pollinators: Yes (Read Jekka's Guide to Pollinators for more information)
• Container suitability: Yes
• UK native: Yes
• Caution: Can occasionally make skin sensitive to light when taken medicinally. Poisonous to liverstock.
• Indoor Sowing: In late spring, into prepared plug trays or pots, do not cover. Put in a cold frame.
• Outdoor Sowing: In early summer, into a well-drained soil with a sunny situation. Thin to 20cm apart.
• Propagation: Division
• Maintenance: (Read Jekka's Blogs on Early Spring, Late Spring and Autumn maintenance)
• Harvest: N/A
St. Johns Wort is probably best known for its use in mild to moderate depression. However, it has other helpful attributes. Traditionally it has been used by herbalists to ease nerve conditions such as neuralgia, sciatica, cold sores and anxiety, particularly that associated with the menopause. Infusing the flowers in oil creates a deep red coloured oil that is used for its vulnery (healing) qualities, for example in wounds, bruises and shingles. It has a long history of use and was named ‘Hypericum’ by the 1st century Greek physician, Dioscorides. The name translates as ‘over an apparition’, a reference to its presumed ability to enable exorcism.
Caution: St Johns Wort should be avoided when taking certain pharmaceutical medicines. These include anti-coagulants, calcium channel blockers, chemotherapy, digoxin, finasteride, HIV medication and immunosuppressants. It may also be wise to avoid taking this herb alongside oral contraceptives as it may increase the body’s metabolism of the drug making its contraceptive action less effective, but the clinical evidence to support this is contradictory. This herb can also cause photosensitivity so should be avoided by anyone with this tendency or who may be taking photo-sensitising medication.
Please note: The information provided here is for educational interest only and is not intended to be used to diagnose or treat significant health problems. Any serious or long-term health concerns should always be discussed with a healthcare professional.
See our blog for more information about the National Institute of Medical Herbalists
Jekka's "How to Grow Herbs" videos, includes Jekka's video on how to sow seeds for an informative step-by-step guide to seed sowing.
Growing indoors? Check out Jekka's blog on indoor herb gardening for some advice.
At Jekka’s we sell herbs in 1 Ltr and 2 Ltr pots. These are established and hardy herb plants that are grown following organic principals and to survive the UK climate. Please read Jekka's blog that contains her top steps to growing on your herbs.
Our herbs are designed to be grown in containers or planted in the garden. Although some herbs will be quite happy indoors, most prefer being outside. Please see our indoor growing blog for more information.
If you think your herbs need a little more attention we always recommend an environmentally friendly solution, and these are Jekka's top three:
- Maxicrop liquid seaweed: 'Feed on Fridays' as Jekka always says for all round good plant health.
- SB Invigorator: a safe and effective insecticide and fungicide to help control a wide range of pest species
- Epsom salts: the horticultural equivalent of what you put in your bath to top up magnesium and stop orange leaves.
One of our three core roots is that we are Environmentally Conscious and for the past 30 years all the herbs grown at Jekka’s have been raised following sustainable, environmentally friendly and organic approaches resulting in a remarkable biodiversity at the herb farm.
Our herb seeds are also untreated and can be used to grow organic herb plants.