St. John's Wort
hypericum tomentosum
Also known as: ["Tomentose St. John's Wort","Feltleaf St. John's Wort"]
Overview
A small, deciduous shrub with yellow flowers and felt-like leaves, native to parts of Europe and Asia.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","drought tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Malpighiales |
| Family: | Hypericaceae |
| Genus: | Hypericum |
| Botanical Name: | Hypericum tomentosum |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: rock gardens, border plantings, or containers in full sun
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"5–35°C"}
- Hardiness: {"zones":"8–10"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent root rot.
- Soil Type: Well-draining, loamy soil with added organic matter.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Annually in late winter or early spring before new growth begins.
- Pruning Intensity: Moderate; remove up to one-third of old growth to rejuvenate the plant.
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily). Tolerates partial shade but may become leggy.
Sunlight Tolerance Tips:
Acclimate plants gradually to intense sunlight to prevent scorching. In hot climates, provide afternoon shade to protect from excessive heat.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun to partial shade
Rotate plants for even light exposure; use reflective mulch to enhance light reflection; monitor for signs of sunburn.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly until runoff, allow soil to dry partially between waterings, and avoid frequent shallow watering.
Soil
well-draining, sandy loam with moderate organic content
pH: Slightly acidic to neutral (pH 6.0–7.0).
Test soil pH annually; amend with compost yearly; ensure pots have drainage holes.
Temperature
Thrives in 65–85°F (18–29°C). Tolerates mild frosts but prefers moderate temperatures year-round.
Avoid sudden temperature fluctuations; protect from frost; ensure good air circulation in hot weather.
Fertilizing
every 4–6 weeks during spring and summer
Apply fertilizer before watering to prevent root burn; use organic options like compost for slow release; stop fertilizing in late autumn.
Propagation
Methods
Stem cuttings taken in late spring or early summer.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Maintain humidity.
Best Time: Late spring to early summer when new growth is firm but not woody.
Environment
High humidity (70–80%), indirect light, and consistent warmth (70–75°F).
Medium
Well-draining mix of peat, perlite, and sand.
Hormone
Rooting hormone is recommended to improve success rates.
Timeline
Roots develop in 4–6 weeks; establish in new pots after 2–3 months.
Tools Needed
Pruners, rooting hormone, small pots, plastic bags or propagator, misting bottle.
Quick Tips
Use healthy, non-flowering stems; maintain humidity with a plastic cover; avoid overwatering.
Pruning & Repotting
Pruning Guide
Method
Selective thinning of branches and light shaping to improve air circulation.
Pruning Plan
Prune to maintain shape, encourage bushiness, and remove dead or weak growth.
Tools
Pruning shears, loppers (for larger branches), sterilizing solution.
Checklist
Sterilize tools; prune dead/damaged wood; make clean cuts; disinfect after use.
Repotting Guide
Best Season
Early spring before active growth starts.
Pot Size
Increase pot size by 2–3 inches in diameter.
Method
Remove plant gently; trim rootbound roots; refresh soil mix; ensure good drainage.
Suggestions
Repot every 2–3 years or when roots fill the container to prevent congestion.
Checklist
Check root health; prepare new pot with drainage holes; use fresh soil mix; water lightly after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture with a finger; water deeply; ensure drainage; avoid wetting foliage.
How to Apply Water Properly
Water directly at the root zone, ensuring even saturation to a depth of 6–8 inches. Water early in the morning to minimize evaporation and allow foliage to dry.
Watering Schedule Tips
Water deeply once every 7–10 days during active growth, reducing frequency to every 2–3 weeks in winter. Adjust based on rainfall and soil moisture retention.
Soil Improvement
Add perlite or coarse sand for drainage; incorporate compost for fertility; use raised beds if drainage is poor.
Temperature Stress Management
Signs of Temperature Issues
Chlorosis or leaf drop in excessive heat; stunted growth or leaf necrosis in cold stress.
Cold Stress
Low temperatures slow growth and may cause leaf drop or tissue damage, especially below 20°F (-6°C).
Solution: Protect with frost cloth or mulch in winter; move potted plants indoors or to a sheltered location.
Hot Stress
Excessive heat can lead to wilting, leaf scorch, or reduced flowering if water and light are not managed.
Solution: Provide afternoon shade, increase watering frequency, and use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Check fertilizer type; follow dilution instructions; apply evenly; avoid contact with stems.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring. Dilute liquid fertilizer to half-strength monthly during growing season; avoid fertilizing in winter.
Common Problems & Solutions
Toxicity Warning
Cats
Slightly ToxicCats that ingest Hypericum tomentosum may experience mild gastrointestinal upset and skin irritation. The plant poses a low risk but should be handled with caution around felines.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
Slightly ToxicIngestion of Hypericum tomentosum by dogs can lead to mild gastrointestinal distress and potential phototoxicity. The plant is not highly toxic but should still be kept out of reach of pets.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
Slightly ToxicHypericum tomentosum contains hypericin and other compounds that can cause phototoxicity and gastrointestinal upset when ingested. The plant's effects are generally mild but can be more pronounced in sensitive individuals.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Hypericum tomentosum toxic to pets?
A: Yes, it is mildly toxic to dogs and cats if ingested.
Q: Does this plant attract wildlife?
A: Yes, it attracts bees, butterflies, and birds.
Q: How often should I water Hypericum tomentosum?
A: Water moderately, allowing the soil to dry slightly between waterings.
Quick Reference
| Family: | Hypericaceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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