St Johns Wort Plant Care
Hypericum perforatum L.
Hypericum perforatum, commonly known as St. John's wort, is a flowering plant in the family Hypericaceae.
Every 7–10 days
Full sun to partial shade
50–80°F
40–70%
What Is the St Johns Wort?
St Johns Wort (Hypericum perforatum) belongs to the Hypericaceae family within the Hypericum genus. St Johns Wort is also known as St. John's wort, Perforate St. John's-wort, Common St. John's wort.
St Johns Wort displays an upright, bushy shrub growth habit, reaching up to 3 inches tall with a spread of approximately 2 inches. St Johns Wort produces bright yellow, star-shaped flowers with prominent stamens.
Leaf size: approximately 4 inches.
How Often Should You Water a St Johns Wort?
Hypericum perforatum requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–10 days
Let soil partially dry between waterings
What Light Does the St Johns Wort Need?
St Johns Wort thrives in full sun to partial shade light conditions. The optimal light range is 200–1000 lux. Avoid placing St Johns Wort in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Full sun to partial shade
200–1000 lux
What Temperature and Humidity Does the St Johns Wort Prefer?
Hypericum perforatum grows best at temperatures between 50°F and 80°F. St Johns Wort prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a St Johns Wort?
Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for St Johns Wort to prevent waterlogging, which leads to root rot and fungal issues.
How Do You Repot a St Johns Wort?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a St Johns Wort?
St Johns Wort can be propagated through softwood cuttings, seeds.
Fertilizing
Every 6 months
During the growing season
Is the St Johns Wort Toxic to Pets and Children?
Non-Toxic
Non-toxic to humans and pets
What Pests and Diseases Affect the St Johns Wort?
St Johns Wort is susceptible to aphids, scale insects, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
What USDA Hardiness Zone Does the St Johns Wort Need?
St Johns Wort grows outdoors in USDA Zone 12a. In cooler regions, grow St Johns Wort as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
St Johns Wort is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Hypericum genus — compare its care with other Hypericum species on PlantoScan.
St Johns Wort tolerates low-light rooms and shaded spots — browse the full list of low-light plants.
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