Alpenrose
rhododendron ferrugineum
Also known as: ["Alpine rose","Ironwort"]
Overview
A small evergreen shrub native to the Alps and Pyrenees, known for its small, leathery leaves and clusters of pinkish-red flowers.
Benefits & Perks
["cold hardy","wildlife attractant (bees, butterflies, birds)","shade tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Ericales |
| Family: | Ericaceae |
| Genus: | Rhododendron |
| Botanical Name: | Rhododendron ferrugineum |
Plant Characteristics
Basic Information
- Category: Shrubs
- Suitable Location: sheltered garden bed with dappled light, or container in a cool, humid environment
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"0–25°C"}
- Hardiness: {"zones":"5–8"}
- Misting: every 2–3 days, especially in dry indoor conditions
- Drainage: Well-draining to fast-draining; must avoid waterlogged conditions.
- Soil Type: Acidic, peaty, well-draining soil with organic matter (e.g., pine bark or compost).
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: high
- Pruning Frequency: Annually after flowering; light pruning can be done as needed.
- Pruning Intensity: Light to moderate; avoid heavy pruning as it may reduce flowering.
Care Details
Ideal Sunlight Coverage:
Partial shade to full shade; 4–6 hours of filtered or morning sunlight; avoid intense afternoon sun.
Sunlight Tolerance Tips:
Acclimate gradually to outdoor light; protect from harsh sun; place in dappled shade or under taller plants for outdoor cultivation.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
partial shade, protected from intense afternoon sun
Avoid direct midday sun; use shade cloth if needed; rotate plant for even light exposure.
Watering
every 7–10 days, allowing soil to dry slightly between waterings
Water deeply to encourage root growth; avoid frequent shallow watering; ensure good drainage to prevent root rot.
Soil
acidic, well-draining, peaty soil mix
pH: Acidic (pH 4.5–6.0).
Use acidic soil mix; avoid lime-based amendments; ensure good drainage to prevent root rot.
Temperature
Cool to moderate temperatures (50–70°F or 10–21°C); prefers cooler climates; sensitive to extreme heat or cold.
Avoid sudden temperature changes; protect from frost; maintain consistent cool temperatures for best growth.
Fertilizing
every 4–6 weeks during active growth (spring to early summer)
Fertilize only during active growth; avoid late-season feeding to prevent new growth vulnerable to frost; water before fertilizing.
Propagation
Methods
Stem cuttings (semi-hardwood); layering is also effective.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Maintain humidity with a propagator or plastic cover.
Best Time: Late spring to early summer when new growth is mature but not woody.
Environment
High humidity (70–90%), warm temperatures (65–75°F or 18–24°C), and indirect light.
Medium
Peat-based mix with perlite or sand for good drainage and moisture retention.
Hormone
Rooting hormone (auxin-based) recommended for higher success rates.
Timeline
6–8 weeks for roots to develop; 1–2 years to establish a mature plant.
Tools Needed
Pruning shears, rooting hormone, peat-based medium, plastic cover or propagator, misting spray bottle.
Quick Tips
Use healthy, disease-free cuttings; maintain consistent humidity; avoid direct sunlight during rooting.
Pruning & Repotting
Pruning Guide
Method
Selective removal of spent flowers (deadheading) and thinning of crowded branches; shape as needed.
Pruning Plan
Prune to maintain shape, encourage flowering, and remove dead or diseased wood; minimal pruning needed as it naturally forms a compact habit.
Tools
Pruning shears, loppers (for larger branches), sterilizing solution.
Checklist
Sterilize tools; prune after flowering; remove dead or crossing branches; shape lightly.
Repotting Guide
Best Season
Early spring before new growth begins; avoid repotting during flowering or dormancy.
Pot Size
Increase pot size by 2–3 inches in diameter; avoid oversized pots to prevent waterlogging.
Method
Gently remove plant; trim any dead roots; repot in fresh, acidic, well-draining soil; ensure good drainage with a layer of gravel at the bottom.
Suggestions
Repot every 2–3 years or when roots fill the container; rhododendrons prefer slightly root-bound conditions.
Checklist
Use acidic soil mix; trim roots if necessary; ensure drainage; water lightly after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply; ensure drainage; adjust frequency by season.
How to Apply Water Properly
Water at the base of the plant, avoiding foliage; apply until water drains from the bottom; ensure even moisture distribution without waterlogging.
Watering Schedule Tips
Water regularly during active growth (spring–summer), allowing soil to dry slightly between waterings; reduce frequency in fall–winter to prevent waterlogging.
Soil Improvement
Add peat moss, pine bark, or compost to increase acidity and organic content; ensure good aeration and drainage.
Temperature Stress Management
Signs of Temperature Issues
Leaf scorch (brown edges) in excessive heat; leaf drop or wilting in cold stress; stunted growth in unsuitable temperatures.
Cold Stress
Leaves may curl, turn purple, or drop; growth slows or halts; buds may fail to open in severe cold.
Solution: Protect with frost cloth or mulch; avoid planting in exposed areas; ensure good air circulation to prevent frost damage.
Hot Stress
Wilting, leaf scorch, or premature leaf drop; reduced flowering; increased susceptibility to pests.
Solution: Provide shade during peak heat; increase humidity with misting; water deeply but avoid waterlogging.
Fertilizing Guide
Fertilizing Checklist
Use acid-loving fertilizer; dilute properly; apply during growing season; avoid contact with roots.
Fertilizing Method
Use a balanced, acid-loving fertilizer (e.g., rhododendron or azalea formula); apply in early spring and midsummer; dilute to half strength to avoid burning.
Common Problems & Solutions
Toxicity Warning
Cats
ToxicRhododendron ferrugineum is toxic to cats due to its grayanotoxin content, which can cause severe gastrointestinal upset and cardiovascular issues. Cats are particularly sensitive to these toxins.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
ToxicGrayanotoxins in Rhododendron ferrugineum are highly toxic to dogs, causing severe gastrointestinal and cardiovascular distress. The toxins interfere with normal cellular function, leading to potentially fatal complications.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
ToxicRhododendron ferrugineum contains grayanotoxins, which disrupt sodium channels in cell membranes, leading to cardiovascular and neurological effects. Ingestion can cause severe poisoning, particularly affecting the heart and nervous system.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Rhododendron ferrugineum toxic to pets?
A: Yes, it is highly toxic to both dogs and cats.
Q: Does Rhododendron ferrugineum attract wildlife?
A: Yes, it attracts bees, butterflies, and birds.
Q: What are the common problems with Rhododendron ferrugineum?
A: Common issues include leaf spots and wilting.
Quick Reference
| Family: | Ericaceae |
| Care: | moderate |
| Light: | partial shade, protected from |
| Water: | every 7–10 days, allowing so |
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