Fierian St. John's wort Plant Care
Hypericum fieriense N.Robson
Updated · Sources · How we source care data
With its striking silver-green leaves covered in tiny black dots, this plant hails from the rugged cliffs of the Canary Islands. Plant collectors are drawn to Hypericum fieriense for its unique and eye-catching foliage, making it a coveted addition to any rare plant collection.
Every 7–10 days
Full sun to partial shade
50–80°F
40–70%
At a glance
How do you care for Fierian St. John's wort?
Plant Fierian St. John's wort in full sun to partial shade (USDA zones 10b–11b) and water a young shrub every 7–10 days until it is established. It tolerates temperatures of 50–80°F (10–27°C). Fertilize it every 6 months during the growing season.
Where Is the Fierian St. John's wort Native To?
What Is the Fierian St. John's wort?
Fierian St. John's wort (Hypericum fieriense) belongs to the Hypericaceae family within the Hypericum genus. Fierian St. John's wort is native to Socotra, an island archipelago that is part of Yemen. Fierian St. John's wort is also known as Fieri hypericum.
Fierian St. John's wort displays an upright, bushy shrub growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Fierian St. John's wort produces bright yellow, star-shaped flowers with prominent stamens.
Leaf size: approximately 4 inches.
How Often Should You Water a Fierian St. John's wort?
Water a young or newly planted Fierian St. John's wort every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.
Watering Frequency
Every 7–10 days
Until established; then in dry spells
What Light Does the Fierian St. John's wort Need?
Fierian St. John's wort thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Fierian St. John's wort Prefer?
Hypericum fieriense tolerates temperatures of 50–80°F. Fierian St. John's wort prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a Fierian St. John's wort?
Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for Fierian St. John's wort to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Fierian St. John's wort?
Feed Fierian St. John's wort every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.
Stop feeding by late summer so new growth can harden before winter.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
Where Should You Plant a Fierian St. John's wort?
Choose a spot with full sun to partial shade and well-draining loamy soil with added organic matter for moisture retention. Avoid low spots where water collects after rain.
Fierian St. John's wort is suited to USDA Zone 10b – 11b.
Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.
How Far Apart Should You Plant a Fierian St. John's wort?
Fierian St. John's wort can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.
Planning a row or hedge? Try the plant spacing calculator.
How Do You Prune a Fierian St. John's wort?
Prune Fierian St. John's wort while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.
If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.
How Do You Care for a Fierian St. John's wort in Winter?
Fierian St. John's wort is frost-tender (hardy to USDA zone 10). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.
How Do You Propagate a Fierian St. John's wort?
Fierian St. John's wort can be propagated through softwood cuttings, seeds. Similar propagation techniques also apply to addington's st. john's wort plant care, which shares the same genus.
Is the Fierian St. John's wort Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Fierian St. John's wort, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Fierian St. John's wort?
Fierian St. John's 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.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Fierian St. John's wort Need?
Fierian St. John's wort grows outdoors in USDA Zone 10b – 11b. It survives winters down to planting zone 10b. Fierian St. John's wort is native to Socotra, an island archipelago that is part of Yemen. In cooler regions, grow Fierian St. John's wort as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 10b – 11b
Keep exploring plants
Fierian St. John's 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.
Hypericum is part of the Hypericaceae plant family — browse all Hypericaceae genera and species.
Fierian St. John's wort thrives in bright light and direct sun — see other bright-light plants.
More Hypericum Species
Other Hypericum species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Hypericum fieriense N.Robson, family Hypericaceae (first published in Bull. Nat. Hist. Mus. (London), Bot. 23: 68 (1993)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Fierian St. John's wort, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Hardiness zone: USDA Zone 10b – 11b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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