Lobelia
Lobelia
Herbaceous annuals and perennials with showy tubular blue, red, or white flowers; popular in borders and containers. Prefer moist, well-drained soil and partial sun.
Caution: Toxic to Pets
Toxicity: toxic
Many Lobelia species contain alkaloids (lobeline) that can cause vomiting, tremors, or more severe symptoms if ingested by pets or humans.
🌱Care Requirements
Light
Place lobelia where it receives bright light with some protection from hot afternoon sun. Ideal locations are east- or north-facing windows, or outdoor sites with morning sun and afternoon shade to preserve blooms and color.
Water
Keep soil consistently moist but not waterlogged. Water thoroughly when the top 1–2 cm is dry; in warm weather check every 2–3 days and reduce frequency in cooler weather. Use well-draining mix to avoid root rot.
Humidity
Lobelia prefers moderate humidity; avoid dry indoor air. Increase humidity by grouping plants, using a pebble tray, or a humidifier, especially during heated indoor winters.
Temperature
Best between 10–25°C (50–77°F). Avoid prolonged exposure below 7°C (45°F) or above 27°C (80°F), which stresses growth and flowering.
🔧Common Problems & Solutions
Wilting and drooping foliage
Cause: Underwatering, high heat, or root stress
Solution: Water thoroughly, move to shadier spot during heat, check roots for compacted soil; mulch containers to retain moisture.
Yellowing leaves and soft stems
Cause: Overwatering or poor drainage causing root rot
Solution: Reduce watering, improve drainage, repot into fresh, airy mix; trim affected roots and foliage if rot is present.
Leggy, sparse growth with fewer flowers
Cause: Insufficient light or lack of regular pinching
Solution: Move to brighter position, pinch back stems to encourage bushiness and repeat deadheading to promote blooms.
Aphids, slugs, or snails feeding on foliage
Cause: Pest infestation in humid or crowded conditions
Solution: Remove pests by hand, use insecticidal soap for aphids, apply slug traps or barriers and improve air circulation.
✂️How to Propagate Lobelia
By seed: sow surface-sown seeds in fine, moist seed mix; press lightly, keep at 18–21°C and maintain humidity; germination in 10–21 days. By stem cuttings: take 5–8 cm healthy tips, remove lower leaves, root in moist perlite or mix under mist in bright indirect light; transplant after roots form. By division: lift clumps in early spring, separate rooted sections and replant with fresh soil, keeping divided plants well watered until established.
🌍Origin & Background
Family: Campanulaceae
Native to: Native to southern Africa (Lobelia erinus); the genus contains species across North and South America and Africa.
Natural Habitat: Found in moist meadows, stream banks, and open woodlands; lobelias favor cool, well-drained soils with steady moisture and partial sun exposure in their native ranges.
🗓Seasonal Care Guide
Winter
Keep plants cooler and reduce watering; maintain bright indirect light and moderate humidity. Protect tender varieties from frost and bring containers indoors if needed.
Spring
Resume regular watering and feed lightly with balanced fertilizer as new growth appears. Pinch tips to encourage bushy growth and transplant or divide if required.
Summer
Provide morning sun and afternoon shade; water frequently to keep soil evenly moist and deadhead spent blooms to prolong flowering.
Fall
Slow feeding and reduce watering as growth slows. In cold climates lift tender types for indoor overwintering or treat as annual and collect seed if desired.
❓Frequently Asked Questions
How often should I water lobelia?
Water when the top 1–2 cm of soil is dry; typically every 2–5 days depending on temperature and container size.
Does lobelia need full sun?
Lobelia prefers bright light with protection from hot afternoon sun; morning sun with afternoon shade is ideal.
Can I grow lobelia indoors?
Yes—provide bright indirect light, consistent moisture, and moderate humidity for indoor cultivation.
Is lobelia safe for pets?
No, many lobelia species contain toxic alkaloids; keep away from pets and children to avoid ingestion.
How do I propagate lobelia?
Propagate from seed, soft-tip stem cuttings, or by dividing established clumps in spring for best results.
Turn These Tips into Daily Plant Chats
Get watering reminders, humidity alerts, and adorable updates straight from your Lobelia. TextMyPlant keeps you on schedule so your plants always look their best.
Start chatting with your plants🌿Related Plant Guides
Tulip
BeginnerTulipa
Spring-flowering bulbous perennials with showy cup-shaped flowers in many colors; grown from bulbs, prefer full sun and well-drained soil, and require a cold dormant period to bloom.
Common yarrow
BeginnerAchillea millefolium
Hardy, low-maintenance perennial herb with feathery leaves and flat clusters of tiny flowers; tolerates poor soils, drought, and full sun.
Baby's-breath
BeginnerGypsophila
Genus of herbaceous flowering plants (baby's-breath) grown for airy clusters of tiny white or pink flowers; prefers full sun and well‑drained, neutral to alkaline soil.
Common hyacinth (Dutch hyacinth)
BeginnerHyacinthus orientalis
Fragrant spring-blooming bulbous perennial with dense spikes of bell-shaped flowers in various colors; commonly grown in gardens and containers; hardy in temperate climates.
Last updated: 11/7/2025