Cardinal Flower
lobelia cardinalis
Also known as: ["Scarlet Lobelia","Red Lobelia"]
Overview
A striking herbaceous perennial known for its vibrant red tubular flowers and lance-shaped leaves.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Asterales |
| Family: | Campanulaceae |
| Genus: | Lobelia |
| Botanical Name: | Lobelia cardinalis |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: moist garden beds or containers near water features
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"5–30°C"}
- Hardiness: {"zones":"4–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Well-draining to prevent waterlogging; avoid heavy clay soils.
- Soil Type: Rich, well-draining, slightly acidic soil with organic matter like peat moss or compost.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Light pruning every 4–6 weeks during the growing season; major pruning in early spring.
- Pruning Intensity: Light to moderate; avoid heavy pruning unless necessary to rejuvenate the plant.
Care Details
Ideal Sunlight Coverage:
Bright indirect light for 6–8 hours daily; can tolerate partial shade, especially in hot climates.
Sunlight Tolerance Tips:
Acclimate plants gradually to direct sunlight to avoid scorching; place in filtered light during peak summer hours.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
partial shade to full sun
Rotate the plant weekly for even growth; provide shade during intense afternoon sun.
Watering
every 5–7 days, more frequently in hot weather
Keep soil consistently moist but not waterlogged; avoid letting the plant dry out completely.
Soil
moist, rich, loamy soil with good drainage
pH: Prefers slightly acidic soil (pH 5.5–6.5).
Ensure soil is never waterlogged; amend with organic matter for better structure; test pH annually.
Temperature
Prefers temperatures between 65–75°F (18–24°C); cooler temperatures (50–60°F or 10–15°C) at night promote better growth.
Avoid placing near drafty windows or heating vents; maintain consistent temperatures to prevent shock.
Fertilizing
every 4–6 weeks during growing season
Apply fertilizer after watering to prevent root burn; flush soil occasionally to prevent salt buildup.
Propagation
Methods
Stem cuttings or division of clumps; stem cuttings are more common for home growers.
Step-by-Step Propagation Guide
- Take a 4–6 inch cutting below a node.
- Remove lower leaves.
- Dip in rooting hormone (optional).
- Plant in moist medium.
- Maintain humidity.
Best Time: Spring or early summer when the plant is actively growing.
Environment
High humidity (70–90%), warm temperatures (70–75°F or 21–24°C), and indirect light.
Medium
Well-draining potting mix with perlite or sand; can also root in water initially.
Hormone
Rooting hormone is optional but recommended for faster rooting.
Timeline
Roots typically form in 2–4 weeks; new growth may appear in 6–8 weeks.
Tools Needed
Pruning shears, rooting hormone, small pots, plastic bags or propagator, misting bottle.
Quick Tips
Keep the medium consistently moist; provide bottom heat for faster rooting; avoid direct sunlight.
Pruning & Repotting
Pruning Guide
Method
Pinch back stems to encourage branching; deadhead spent flowers to promote continuous blooming.
Pruning Plan
Prune to maintain shape, encourage bushier growth, and remove spent flowers to prolong blooming.
Tools
Clean, sharp pruning shears or scissors; gloves.
Checklist
Sterilize tools; prune in early morning; remove dead or diseased parts; avoid over-pruning.
Repotting Guide
Best Season
Early spring before the active growing season begins.
Pot Size
Choose a pot one size larger (1–2 inches wider in diameter) than the current one.
Method
Remove the plant gently; trim any circling roots; place in a new pot with fresh soil; water thoroughly after repotting.
Suggestions
Repot every 1–2 years or when roots fill the pot; beneficial for maintaining vigor and blooming.
Checklist
Select appropriate pot; prepare fresh soil mix; water plant a day before repotting; handle roots carefully.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture daily; water thoroughly until water drains from the bottom; ensure proper drainage.
How to Apply Water Properly
Water at the base of the plant, ensuring even moisture distribution to the root zone; allow excess water to drain away to prevent waterlogging.
Watering Schedule Tips
Water deeply when the top inch of soil feels dry; reduce frequency in winter to prevent root rot.
Soil Improvement
Add perlite or sand for drainage; incorporate compost for fertility; adjust pH with peat moss or sulfur if needed.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves, or stunted growth in extreme heat or cold; leaf drop in prolonged cold.
Cold Stress
Slows growth and can cause leaf discoloration; prolonged exposure to temperatures below 50°F (10°C) may lead to plant death.
Solution: Move potted plants indoors during cold spells; provide a protective layer of mulch for in-ground plants.
Hot Stress
Leaves may wilt, scorch, or drop; flowering may be reduced in excessive heat.
Solution: Provide shade during peak heat; increase humidity around the plant; water more frequently to compensate for evaporation.
Fertilizing Guide
Fertilizing Checklist
Use diluted fertilizer; fertilize during active growth; stop in winter; flush soil periodically.
Fertilizing Method
Use a balanced liquid fertilizer diluted to half strength every 4–6 weeks during the growing season (spring and summer); avoid fertilizing in winter.
Common Problems & Solutions
Toxicity Warning
Cats
ToxicCats are also susceptible to the toxic effects of Lobelia cardinalis. The alkaloids in the plant can cause severe gastrointestinal and neurological symptoms, as well as respiratory issues in felines.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
ToxicIn dogs, ingestion of Lobelia cardinalis can lead to severe toxicity due to the presence of lobeline and other alkaloids. These compounds can cause significant gastrointestinal upset, neurological effects, and respiratory distress in canines.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
ToxicLobelia cardinalis contains lobeline and other alkaloids that can cause significant physiological effects, including respiratory depression, neuromuscular effects, and gastrointestinal distress. The plant's toxicity is due to its ability to interfere with the nervous system and cardiovascular functions.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Lobelia cardinalis toxic to pets?
A: Yes, it is mildly toxic to dogs and cats if ingested.
Q: Does Lobelia cardinalis attract wildlife?
A: Yes, its vibrant flowers attract hummingbirds, bees, and butterflies.
Q: How should Lobelia cardinalis be watered?
A: It prefers consistently moist soil and should not be allowed to dry out completely.
Quick Reference
| Family: | Campanulaceae |
| Care: | moderate |
| Light: | partial shade to full sun |
| Water: | every 5–7 days, more frequen |
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