Stinking Iris, Gladdon
iris foetidissima
Also known as: ["Stinking Gladwyn","Stinking Iris"]
Overview
A perennial iris species native to Western Europe, known for its unpleasant odor when bruised and its bright orange-red seeds.
Benefits & Perks
["drought tolerant","shade tolerant","wildlife attractant (bees, butterflies, birds)"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Liliopsida |
| Order: | Asparagales |
| Family: | Iridaceae |
| Genus: | Iris |
| Botanical Name: | Iris foetidissima |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: border plantings or woodland gardens
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"0–35°C"}
- Hardiness: {"zones":"6–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent rhizome rot.
- Soil Type: Well-draining, loamy soil with added organic matter; tolerates poor soils but thrives with moderate fertility.
Maintenance Level
- Maintenance Level: low
- Toughness Level: moderate
- Pruning Frequency: As needed, typically in late winter or early spring before new growth emerges.
- Pruning Intensity: Light; focus on removing only dead or diseased parts.
Care Details
Ideal Sunlight Coverage:
Full sun to partial shade (4–6 hours of direct sunlight daily); tolerates dappled light in hotter climates.
Sunlight Tolerance Tips:
Acclimate gradually to intense sunlight; protect from harsh afternoon sun in hot regions; place in partial shade if leaves scorch.
Care Requirements
Care Difficulty
easymoderate
Sunlight
partial shade to full sun
Morning sun is ideal; avoid hot afternoon sun; adjust placement based on seasonal light intensity.
Watering
every 7–10 days during active growth, reduce in winter
Water at the base to avoid foliage, ensure soil is moist but not waterlogged, and reduce watering in winter.
Soil
well-drained, neutral to alkaline soil
pH: Slightly acidic to neutral (pH 6.0–7.0).
Ensure excellent drainage; avoid heavy clay soils; enrich with organic matter for better growth.
Temperature
Hardy in USDA zones 5–9; tolerates cold winters and moderate heat; prefers temperatures between 60–75°F (15–24°C) during active growth.
Protect from extreme cold with mulch; water deeply in heat; adjust sunlight exposure seasonally.
Fertilizing
every 2–3 months during spring and summer
Fertilize lightly in spring; avoid over-fertilizing; stop feeding in late summer.
Propagation
Methods
Rhizome division or seed sowing; division is faster but seeds offer genetic diversity.
Step-by-Step Propagation Guide
- Divide rhizomes into sections with healthy roots.
- Plant seeds shallowly in pots.
- Keep moist and warm until germination.
Best Time: Divide rhizomes in late summer or early fall; sow seeds in autumn for spring germination.
Environment
Warm, humid conditions for rhizomes; cool, moist conditions for seeds; partial shade for both.
Medium
Well-draining soil mix with added grit or sand for rhizomes; sterile seed starting mix for seeds.
Hormone
Not necessary for rhizome division; optional for seeds to encourage germination.
Timeline
Rhizomes establish in 1–2 months; seeds may take 1–2 years to germinate and establish.
Tools Needed
Sharp knife, pruning shears, pots, seed starting mix, rooting hormone (optional).
Quick Tips
Divide every 3–4 years to maintain vigor; scarify seeds for better germination; protect young plants from frost.
Pruning & Repotting
Pruning Guide
Method
Cut back old leaves at the base; trim spent flower stalks after blooming.
Pruning Plan
Minimal pruning needed; remove dead or damaged foliage to maintain appearance and prevent disease.
Tools
Sharp bypass pruners, gloves, disinfectant for tools.
Checklist
Disinfect tools; cut cleanly at the base; remove only dead/damaged parts; clean up debris.
Repotting Guide
Best Season
Late summer or early fall after flowering ceases and before dormancy.
Pot Size
Increase pot size by 2–3 inches if repotting in a container; for ground plants, ensure spacing of 12–18 inches.
Method
Gently lift rhizomes, remove dead roots, replant in fresh soil with the top of the rhizome exposed, ensure good drainage.
Suggestions
Not typically needed for outdoor plants; container-grown irises may need repotting every 3–4 years if crowded.
Checklist
Prepare new soil mix; lift rhizome carefully; trim dead roots; replant at correct depth; water thoroughly.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply at the base; ensure proper drainage; reduce frequency in winter.
How to Apply Water Properly
Water directly at the root zone until the soil is evenly moist, ensuring water penetrates deeply but excess drains away; water in the morning to minimize evaporation and fungal risk.
Watering Schedule Tips
Water deeply once a week during active growth, reducing frequency in winter dormancy; adjust based on rainfall and soil moisture retention.
Soil Improvement
Add compost or well-rotted manure for fertility; incorporate sand or grit for drainage; mulch with organic matter.
Temperature Stress Management
Signs of Temperature Issues
Chlorosis or browning of leaves in excessive heat; leaf drop or stunted growth in prolonged cold.
Cold Stress
Leaves may yellow or wilt; growth slows or halts; rhizomes can rot in waterlogged soil during freeze.
Solution: Mulch heavily around rhizomes in fall; ensure well-draining soil; protect from freezing winds.
Hot Stress
Leaves may scorch, wilt, or drop; flowering may be reduced; rhizomes can desiccate in extreme heat.
Solution: Provide partial shade during peak heat; water deeply and mulch to retain soil moisture; avoid overhead watering.
Fertilizing Guide
Fertilizing Checklist
Use balanced fertilizer; apply in early spring; avoid late-season feeding.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring; avoid high-nitrogen formulas; discontinue in late summer to prepare for dormancy.
Common Problems & Solutions
Toxicity Warning
Cats
Slightly ToxicCats are sensitive to the compounds in Iris foetidissima, particularly the rhizomes and roots. Ingestion can cause gastrointestinal irritation and mild systemic effects, though severe toxicity is rare.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
Slightly ToxicIn dogs, ingestion of Iris foetidissima can lead to mild to moderate gastrointestinal upset due to the presence of iridoid glycosides. While generally not life-threatening, ingestion should be avoided to prevent discomfort.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
Slightly ToxicIris foetidissima contains iridoid glycosides and other compounds that can cause gastrointestinal distress and mild systemic effects upon ingestion. The rhizomes and roots are the most toxic parts due to their higher concentration of these compounds.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Why is it called 'Stinking Iris'?
A: The plant emits an unpleasant odor when its leaves or rhizomes are bruised or crushed.
Q: Is Iris foetidissima toxic to pets?
A: It is mildly toxic to dogs and cats if ingested, causing gastrointestinal upset.
Q: Does this iris require full sun?
A: It can tolerate partial shade and is suitable for woodland gardens.
Quick Reference
| Family: | Iridaceae |
| Care: | easy |
| Light: | partial shade to full sun |
| Water: | every 7–10 days during activ |
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