Star of Persia
allium cristophii
Also known as: ["Ornamental Onion","Persian Onion"]
Overview
A bulbous perennial known for its large, spherical umbels of star-shaped flowers that resemble a celestial display.
Benefits & Perks
["long-flowering","deer resistant","wildlife attractant (bees, butterflies, birds)","drought tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Liliopsida |
| Order: | Asparagales |
| Family: | Amaryllidaceae |
| Genus: | Allium |
| Botanical Name: | Allium cristophii |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or border in full sun
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–30–35°C"}
- Hardiness: {"zones":"4–8"}
- Misting: rarely required
- Drainage: Fast-draining
- Soil Type: Well-drained, sandy loam with organic matter; avoid heavy clay.
Maintenance Level
- Maintenance Level: low
- Toughness Level: high
- Pruning Frequency: As needed after flowering; remove dead foliage in late fall or early spring.
- Pruning Intensity: Light
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily); tolerates partial shade but may produce fewer blooms.
Sunlight Tolerance Tips:
Acclimate plants gradually if moving from shade to full sun; protect from intense midday sun in hot climates; ensure good air circulation to prevent fungal issues.
Care Requirements
Care Difficulty
easyEasy
Sunlight
full sun
Plant in a south-facing location; avoid dense shade; rotate pots for even light exposure.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly but infrequently to encourage deep root growth; allow soil to dry between waterings; avoid overwatering, especially during dormancy.
Soil
well-draining, sandy or loamy soil
pH: Slightly alkaline to neutral (pH 6.5–7.5)
Ensure excellent drainage; avoid waterlogging; amend with compost if soil is poor.
Temperature
Hardy in USDA zones 4–8; prefers cool to moderate temperatures (60–75°F or 15–24°C); tolerates cold winters but requires well-drained soil to prevent frost heave.
Protect bulbs from excessive moisture in winter; water deeply during heatwaves; avoid planting in areas with extreme temperature fluctuations.
Fertilizing
annually in early spring with a balanced, slow-release fertilizer
Fertilize sparingly; apply fertilizer before watering to prevent root burn; focus on phosphorus for bulb development.
Propagation
Methods
Division of bulbs; occasionally by seed.
Step-by-Step Propagation Guide
- Dig up mature bulbs.
- Separate offsets.
- Replant at the same depth.
- Water lightly until established.
Best Time: Divide bulbs in late summer or early fall after foliage has died back; sow seeds in fall for spring germination.
Environment
Full sun; well-drained soil; protect from excessive moisture during establishment.
Medium
Well-drained bulb mix or sandy loam; add perlite for aeration.
Hormone
Not required for bulb division; optional for seed propagation.
Timeline
Bulbs establish quickly in 1–2 seasons; seeds may take 2–3 years to flower.
Tools Needed
Garden fork, sharp knife, gloves.
Quick Tips
Divide bulbs every 3–4 years to maintain vigor; store bulbs in a cool, dry place if not planting immediately.
Pruning & Repotting
Pruning Guide
Method
Snip flower stalks at the base; pull or cut dead foliage; avoid cutting green leaves.
Pruning Plan
Minimal pruning needed; remove spent flower stalks to encourage bulb development; tidy up dead foliage after it yellows.
Tools
Hand pruners, gloves.
Checklist
Remove spent flowers; cut dead foliage; avoid damaging bulbs; clean tools after use.
Repotting Guide
Best Season
Not applicable; if container-grown, repot in fall when dormant.
Pot Size
Not applicable; if repotting, choose a pot 2–3 inches wider than the current one.
Method
Not applicable; if repotting, use a well-drained mix and plant bulbs at the correct depth.
Suggestions
Not typically repotted; bulbs are planted directly in the ground or containers and left undisturbed for several years.
Checklist
Not applicable; if repotting, ensure good drainage; plant at the correct depth; water lightly.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply at base; ensure drainage; adjust frequency by season.
How to Apply Water Properly
Water directly at the base of the plant, ensuring moisture reaches the root zone; water early in the morning to minimize evaporation and fungal issues; ensure excess water drains away to prevent root rot.
Watering Schedule Tips
Water deeply once every 7–10 days during active growth in spring and early summer; reduce frequency to every 2–3 weeks in late summer and fall as foliage dies back; avoid watering in winter when dormant.
Soil Improvement
Add sand or perlite to improve drainage; incorporate compost for fertility; raise beds in heavy soils.
Temperature Stress Management
Signs of Temperature Issues
Chlorosis or leaf burn in excessive heat; soft, mushy bulbs in cold, wet soil; delayed or sparse flowering in insufficient cold exposure.
Cold Stress
Bulbs can rot if soil remains waterlogged during winter; foliage may become discolored or die back prematurely.
Solution: Plant bulbs in well-drained soil; add a layer of mulch for insulation; avoid overwatering in fall and winter.
Hot Stress
Bulbs may fail to bloom if exposed to prolonged heat without adequate water; foliage may wilt or scorch.
Solution: Provide supplemental water during dry spells; plant in areas with afternoon shade if possible; ensure good air circulation.
Fertilizing Guide
Fertilizing Checklist
Use balanced fertilizer; apply in early spring; avoid over-fertilizing; stop after flowering.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring as foliage emerges; avoid high-nitrogen fertilizers; discontinue fertilizing after flowering.
Common Problems & Solutions
Toxicity Warning
Cats
ToxicCats are highly sensitive to Allium cristophii, which can cause severe hemolytic anemia due to the plant's organosulfur compounds. Even small amounts can be harmful.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
ToxicIn dogs, ingestion of Allium cristophii can lead to oxidative damage to red blood cells, resulting in hemolytic anemia. The toxicity is due to the plant's high concentration of organosulfur compounds.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
ToxicAllium cristophii contains compounds that can cause gastrointestinal distress and other systemic effects upon ingestion. The plant's sulfur-containing compounds are responsible for its pungent odor and potential toxicity.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: How tall does Allium cristophii grow?
A: It typically reaches 12–24 inches in height.
Q: Does it require full sun?
A: Yes, it thrives in full sun but can tolerate partial shade.
Q: Is it deer-resistant?
A: Yes, its strong onion scent deters deer.
Quick Reference
| Family: | Amaryllidaceae |
| Care: | easy |
| Light: | full sun |
| Water: | every 7–10 days during activ |
Get Expert Care Tips
Download the Plantious app for personalized care reminders and plant identification!
Google Play App Store
