St. John's Wort
Hypericum perforatum · Perennial
Grown for its flowers, which are harvested with the leaves for tea, oil, tincture or poultice. Needs more light than almost any other herb on this list.
What it needs indoors
- Light
- Full sunMore than 8 hours full sun daily
- Water
- Keep moistKeep the soil moist
- Temperature
- 65–70°F
- Growing medium
- Well-draining; terra cotta or plastic
- Native range
- Open sunny grassland across Europe and western Asia
- Difficulty
- Beginner
What usually goes wrong
Healthy leafy plant that never flowers
Light, and nothing else. It comes off open grassland with nothing overhead at any point in the day and wants more direct sun than almost anything else grown indoors.
Fix: Eight hours and up of direct sun, which in most homes means a grow light filling the gap. There is no harvest worth taking without flowers, so this is the one to solve first.
Lower leaves drop after a hot dry spell
It is a sun plant but not a dry one. Full-sun herbs tend to get treated like Mediterranean shrubs, and this one wants steady moisture at the roots.
Fix: Keep the soil moist rather than letting it swing between soaked and bone dry. A terra cotta pot in strong light dries fast, so check it daily in summer.
Woody, sparse and untidy by the end of the season
It piles up bare stems fast when nothing is ever taken off it.
Fix: Cut the whole plant back hard in late winter before new growth starts. It flowers on the current season's wood, so a hard cut costs you nothing.
How to grow St. John's Wort
Wants the same conditions
Grow these alongside St. John's Wort and one watering routine will suit them all.