Larkspur vs Old Man's Beard Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Larkspur

Larkspur

Delphinium spp.

VS
Old Man's Beard

Old Man's Beard

Usnea spp.

Larkspur

Larkspur

Delphinium spp.

Larkspurs are annual or perennial herbaceous plants known for their tall, erect flower spikes adorned with spurred blossoms. They are primarily outdoor plants, prized for their vibrant colors ranging from blues and purples to pinks and whites. Larkspurs typically grow to heights of 1 to 6 feet, depending on the species and cultivar. Their showy flowers make them popular choices for cottage gardens, borders, and cut flower arrangements. Attempting to grow them indoors is challenging due to their high light requirements and need for specific temperature conditions.

Ranunculaceae Primarily Northern Hemisphere, including Europe, Asia, and North America
✨ Features: Attracts pollinators (bees, butterflies), excellent cut flowers
📖 Read Complete Larkspur Guide
Old Man's Beard

Old Man's Beard

Usnea spp.

Old Man's Beard is a lichen, not a plant. It's a symbiotic relationship between a fungus and an alga or cyanobacterium. It appears as stringy, hair-like strands hanging from trees and shrubs. Its color ranges from pale green to grayish-green. It thrives in humid environments with clean air. People collect it for its purported medicinal properties and decorative uses. It is primarily an outdoor organism and cannot be successfully grown indoors.

Parmeliaceae Worldwide, various species have different distributions
✨ Features: Indicator of air quality; sensitive to pollution.
📖 Read Complete Old Man's Beard Guide

Quick Plant Comparison

Feature Larkspur Old Man's Beard
Light Full sun (at least 6-8 hours of direct sunlight daily) Bright, indirect light outdoors. Full sun can scorch it in dry conditions.
Watering Outdoors: Every 3-7 days, depending on weather and soil drainage. Indoors (not recommended): Extremely difficult to maintain proper moisture levels. Dependent on environmental humidity; mist when dry
Humidity 40-60% 60-90%
Temperature 15-24°C 5-25°C
Care Level Expert Expert
Growth Rate Moderate Slow
Max Height Outdoors: 0.3-1.8 meters (1-6 feet). Indoors: Highly unlikely to thrive, stunted if survives. Variable, up to several feet long depending on the species and environment.
Pet Safety ❌ Toxic To Pets ✅ Safe
Soil Well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.0) Does not grow in soil. Attaches to tree bark or other surfaces.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly (weeding, watering, deadheading) 5 minutes weekly (for misting if needed).

🔬 Botanical Information — Comparing These Plants

Larkspur

Scientific Name Delphinium spp.
Family Ranunculaceae
Native To Primarily Northern Hemisphere, including Europe, Asia, and North America
Also Known As Larkspur, Delphinium
Leaves Leaves are deeply divided and finely cut, giving them a feathery appearance. The color is typically green to bluish-green.
Flowers Larkspurs produce showy, spurred flowers in a variety of colors, including blue, purple, pink, and white. Flowering occurs primarily in the summer months. They rarely, if ever, flower indoors.

Old Man's Beard

Scientific Name Usnea spp.
Family Parmeliaceae
Native To Worldwide, various species have different distributions
Also Known As Old Man's Beard, Tree Moss, Beard Lichen
Leaves Does not have leaves. Consists of thread-like or strap-shaped structures that are pale green to grayish-green in color.
Flowers Does not flower.

📏 Size & Growth — Plant Comparison

Larkspur

Height Outdoors: 0.3-1.8 meters (1-6 feet). Indoors: Highly unlikely to thrive, stunted if survives.
Spread 0.3-0.6 meters (1-2 feet)
Growth Rate Moderate
Growth Pattern Upright, erect growth habit with tall flower spikes. They typically form clumps or colonies in the garden.

Old Man's Beard

Height Variable, up to several feet long depending on the species and environment.
Spread Variable, depending on the host tree and environmental conditions.
Growth Rate Slow
Growth Pattern Hangs in long, stringy strands from tree branches and other surfaces.

🌱 Propagation — Comparing Plant Growth

Larkspur

Methods: Seed, Division (for perennials)

Difficulty: Moderate

Tips: For seeds, cold stratification (refrigeration for several weeks) improves germination. Sow seeds in early spring or fall. Divide perennial clumps in early spring or fall.

Old Man's Beard

Methods: Fragmentation (pieces breaking off and attaching to new surfaces).

Difficulty: Moderate

Tips: Ensure high humidity and a suitable substrate (tree bark). Success is not guaranteed.

✨ Benefits & Features — Comparing Plant Value

Larkspur

Larkspurs are known for their distinctive spurred flowers and tall, erect flower spikes. Their vibrant colors and ability to attract pollinators make them a popular choice for cottage gardens. They are also relatively short-lived perennials or annuals, requiring regular replanting or reseeding.

  • ✓ Attracts pollinators to your garden
  • ✓ Provides beautiful cut flowers
  • ✓ Adds vibrant color and height to your landscape
  • ✓ Can be used in traditional medicine (with extreme caution and expert knowledge)
  • ✓ Offers a sense of accomplishment for experienced gardeners
  • ⚠️ Toxic to pets

Old Man's Beard

It is a lichen, not a plant, representing a symbiotic relationship between a fungus and an alga. Its presence indicates good air quality, making it a valuable environmental indicator.

  • ✓ Air quality indication
  • ✓ Aesthetic appeal in natural settings
  • ✓ Potential medicinal properties
  • ✓ Educational value
  • ✓ Supports biodiversity
  • 🐾 Pet Safe

📅 Maintenance Schedule — Plant Care Comparison

Larkspur

Repotting Not applicable as indoor growing is not recommended. If attempted, repot annually in spring.
Pruning Deadhead spent flowers to encourage more blooms. Cut back stems after flowering to promote bushier growth.
Fertilizing Balanced fertilizer (10-10-10) applied at half strength every 4-6 weeks during the growing season (spring and summer)
Seasonal Care Spring: Plant seeds or seedlings. Summer: Water regularly, fertilize. Fall: Deadhead spent flowers, divide perennials. Winter: Dormant; protect from extreme cold.

Old Man's Beard

Repotting Not applicable.
Pruning Not applicable.
Fertilizing Not applicable; obtains nutrients from the air and rainwater.
Seasonal Care Maintain high humidity during dry seasons. Protect from extreme temperatures.

🌞 Light Requirements

Larkspur

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Old Man's Beard

Bright, indirect light outdoors. Full sun can scorch it in dry conditions.

Low light tolerant: ❌ No

💧 Watering Needs

Larkspur

Water deeply when the top inch of soil feels dry. Avoid overhead watering to prevent fungal diseases. Overwatering can lead to root rot, indicated by yellowing leaves and wilting. Underwatering results in dry, crispy leaves and stunted growth.

Old Man's Beard

Requires high humidity and moisture. In dry climates, misting may be necessary, but it primarily obtains moisture from the air.

🌡️ Temperature & Humidity

Larkspur

Temperature: 15-24°C

Humidity: 40-60%

Old Man's Beard

Temperature: 5-25°C

Humidity: 60-90%

🤔 Which Plant Is Right For You?

Larkspur

Larkspur

Delphinium spp.
Care: Expert Time: 30 minutes weekly (weeding, watering, deadheading) Beginner: No

Experienced gardeners seeking vibrant, tall flowers for their outdoor gardens.

✅ Choose This Plant If...

  • You have a sunny outdoor garden and want to attract pollinators.
  • You love cut flowers and want to grow your own.
  • You are an experienced gardener looking for a rewarding challenge.
  • You appreciate the vibrant colors and tall stature of Larkspurs.
  • You want to add a classic cottage garden element to your landscape.

❌ Skip This Plant If...

  • You have pets or small children who might ingest the plant.
  • You lack a sunny outdoor space.
  • You are a beginner gardener.
  • You prefer low-maintenance plants.
  • You are looking for an indoor plant.
📍 Ideal Location: Outdoor garden with full sun exposure
🎨 Style: Cottage, Traditional, Romantic
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the seeds, are toxic to dogs, cats, horses, and humans. Symptoms include gastrointestinal upset (vomiting, diarrhea), weakness, and in severe cases, respiratory or cardiac failure. Contains diterpenoid alkaloids.
Old Man's Beard

Old Man's Beard

Usnea spp.
Care: Expert Time: 5 minutes weekly (for misting if needed). Beginner: No

Outdoor environments with high humidity and clean air.

✅ Choose This Plant If...

  • You live in a naturally humid environment with clean air.
  • You want to study lichens and their role in the ecosystem.
  • You are interested in traditional medicine and the potential uses of Usnea.
  • You have a shaded outdoor area where you can provide high humidity.
  • You want a natural air quality indicator.

❌ Skip This Plant If...

  • You live in a dry climate.
  • You have poor air quality.
  • You want an easy-to-care-for houseplant.
📍 Ideal Location: Outdoor areas with high humidity and clean air, such as forests or shaded gardens.
🎨 Style: Naturalistic, Woodland, Cottagecore
🏠 Apartment Friendly: No
⚠️ Generally considered non-toxic to humans and animals, but ingestion of large quantities may cause digestive upset.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Old Man's Beard ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Larkspur has moderate growth, while Old Man's Beard grows slow.

💡 Pro Tips For Comparing These Plants

Larkspur Care Tips

Larkspurs are challenging to grow indoors due to their need for full sun, cool temperatures, and well-draining soil. They are best suited for outdoor gardens. Indoor attempts often result in weak, leggy growth and a lack of flowering. Maintaining proper moisture levels is also crucial.

  • Provide support for tall flower spikes to prevent them from bending or breaking.
  • Ensure good air circulation to prevent fungal diseases.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Protect from strong winds.
  • Amend soil with compost before planting to improve drainage and fertility.
❄️ Winter: In colder climates, mulch around the base of the plant to protect the roots from freezing. For annual varieties, collect seeds for replanting in the spring. Perennial varieties may benefit from a light pruning after the first frost.
☀️ Summer: Water regularly, especially during dry spells. Fertilize every 4-6 weeks with a balanced fertilizer. Provide support for tall flower spikes to prevent them from bending or breaking. Monitor for pests and diseases.

Old Man's Beard Care Tips

Old Man's Beard is an outdoor lichen that is extremely difficult to cultivate indoors. It requires very high humidity, clean air, and specific lighting conditions. It is not a suitable houseplant and will likely die indoors.

  • Provide high humidity through regular misting or a humidifier.
  • Ensure good air circulation to prevent fungal growth.
  • Protect from direct sunlight, especially during the hottest part of the day.
  • Monitor for signs of drying out and adjust humidity accordingly.
  • Avoid using tap water for misting, as it can contain minerals that harm the lichen.
❄️ Winter: Protect from extreme cold and drying winds. Ensure adequate humidity.
☀️ Summer: Provide shade during the hottest part of the day. Increase humidity if necessary.

⚠️ Common Problems & Solutions — Plant Care Comparison

Larkspur

Common Issues: Powdery mildew, Botrytis blight (gray mold), Aphids, Spider mites
Solutions: Powdery mildew/Botrytis: Improve air circulation, use fungicide. Aphids/Spider mites: Insecticidal soap or neem oil.

Old Man's Beard

Common Issues: Drying out, air pollution, lack of humidity, fungal infections.
Solutions: Increase humidity through misting or humidifiers. Ensure good air circulation. Treat fungal infections with appropriate fungicides (though this is difficult to do without harming the lichen).

❓ Frequently Asked Questions — Comparing These Plants

Larkspur

What are the light requirements for Larkspur?

Larkspur demands abundant sunshine to flourish. Aim for a location that receives at least six hours of direct sunlight each day. Morning sun is especially beneficial, as it helps to dry the foliage and reduce the risk of fungal diseases. If you live in a hot climate, providing some afternoon shade can prevent the plant from scorching.

How do I care for Larkspur?

Larkspur thrives in full sun, requiring at least 6 hours of direct sunlight daily to produce abundant blooms. Plant in well-draining soil, amending heavy clay with compost to improve drainage. Water regularly, especially during dry periods, keeping the soil consistently moist but not waterlogged. Fertilize every 4-6 weeks with a balanced, slow-release fertilizer or a bloom-boosting formula to encourage flowering.

How do I propagate Larkspur?

Larkspur can be propagated through seeds, division, and stem cuttings.

Old Man's Beard

What are the light requirements for Old Man's Beard?

Old Man’s Beard thrives in bright, indirect light. Direct sunlight can scorch its delicate foliage, causing it to dry out and turn brown. The ideal location is near an east- or west-facing window where it receives filtered sunlight. If you’re using artificial light, provide it with several hours of fluorescent or LED grow lights daily.

How do I care for Old Man's Beard?

Caring for Old Man’s Beard is relatively simple, but understanding its needs is crucial for its health and longevity. Place it in a location with bright, indirect light. Avoid direct sunlight, which can scorch the delicate foliage. Water by misting the plant thoroughly 2-3 times a week, or soaking it in water for 15-30 minutes every 1-2 weeks. After soaking, gently shake off excess water to prevent rot.

How do I propagate Old Man's Beard?

Old Man’s Beard is primarily propagated through pups, or offsets, that grow from the main plant. Once a pup reaches about one-third the size of the mother plant, it can be carefully separated. Gently pull or cut the pup from the main strand, ensuring you don’t damage either plant.

Last updated: May 8, 2026 — Plant care data reviewed and verified by our editorial team.