Alyssum 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.
Alyssum
Lobularia maritima
Sweet Alyssum (Lobularia maritima) is a low-growing, spreading annual or short-lived perennial, typically grown as an annual. It reaches a height of 6-12 inches and spreads 12-18 inches wide. It features masses of tiny, fragrant flowers, usually white but also available in pink, purple, and yellow shades. Primarily an outdoor plant, it's popular for borders, rock gardens, and containers due to its profuse blooms and sweet honey-like scent. While it can be attempted indoors, maintaining sufficient light and cool temperatures is challenging.
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.
Quick Plant Comparison
| Feature | Alyssum | Old Man's Beard |
|---|---|---|
| Light | Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours daily. | Bright, indirect light outdoors. Full sun can scorch it in dry conditions. |
| Watering | Every 2-3 days outdoors in warm weather; every 5-7 days indoors, depending on light and temperature. | Dependent on environmental humidity; mist when dry |
| Humidity | 30-50% | 60-90% |
| Temperature | 15-24°C | 5-25°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Slow |
| Max Height | 6-12 inches (indoors, typically smaller) | Variable, up to several feet long depending on the species and environment. |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining potting mix. A mix of potting soil, perlite, and vermiculite is suitable. | Does not grow in soil. Attaches to tree bark or other surfaces. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 15 minutes weekly | 5 minutes weekly (for misting if needed). |
🔬 Botanical Information — Comparing These Plants
Alyssum
| Scientific Name | Lobularia maritima |
|---|---|
| Family | Brassicaceae |
| Native To | Mediterranean region, Canary Islands |
| Also Known As | Sweet Alyssum, Sweet Alison |
| Leaves | Small, lance-shaped, and grayish-green. The leaves are typically less than an inch long and have a slightly hairy texture. |
| Flowers | Flowers profusely outdoors. Indoors, flowering is possible with sufficient light. The flowers are tiny, four-petaled, and typically white, but also available in pink, purple, and yellow shades. They are clustered together in masses, creating a showy display. |
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
Alyssum
Old Man's Beard
🌱 Propagation — Comparing Plant Growth
Alyssum
Methods: Seed, Stem cuttings
Difficulty: Easy
Tips: For seeds, sow indoors 6-8 weeks before the last frost or directly outdoors after the last frost. For stem cuttings, take 2-3 inch cuttings and root them in water or moist potting mix.
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
Alyssum
Sweet Alyssum is known for its profuse blooms and sweet, honey-like fragrance. Its low-growing, spreading habit makes it ideal for borders and rock gardens. It is also attractive to beneficial insects.
- ✓ Attracts pollinators to the garden.
- ✓ Provides a sweet, honey-like fragrance.
- ✓ Adds a splash of color to borders and containers.
- ✓ Can be used as a ground cover.
- ✓ Provides a calming aesthetic.
- ⚠️ 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
Alyssum
Old Man's Beard
🌞 Light Requirements
Alyssum
Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours 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
Alyssum
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Allow the soil to drain completely after watering. Indoors, monitor closely as soil dries out faster in bright light.
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
Alyssum
Temperature: 15-24°C
Humidity: 30-50%
Old Man's Beard
Temperature: 5-25°C
Humidity: 60-90%
🤔 Which Plant Is Right For You?
Alyssum
Lobularia maritimaExperienced gardeners who want a fragrant, flowering plant for outdoor borders, rock gardens, or containers.
✅ Choose This Plant If...
- You want a plant with a sweet, honey-like fragrance.
- You need a low-growing plant for borders or rock gardens.
- You want to attract pollinators to your garden.
- You enjoy plants that bloom profusely.
- You are an experienced gardener willing to provide the high light levels needed indoors.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You cannot provide very bright, direct light.
- You prefer low-maintenance indoor plants.
Old Man's Beard
Usnea spp.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.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Alyssum has moderate growth, while Old Man's Beard grows slow.
💡 Pro Tips For Comparing These Plants
Alyssum Care Tips
Sweet Alyssum is primarily an outdoor plant. Indoor cultivation is challenging due to its high light requirements and preference for cooler temperatures. It needs very bright, direct light and well-draining soil. Overwatering and lack of sufficient light are common problems indoors.
- Provide at least 6 hours of direct sunlight daily for indoor plants.
- Use well-draining soil to prevent root rot.
- Deadhead spent flowers regularly to encourage continuous blooming.
- Fertilize every 2-4 weeks during the growing season.
- Monitor for pests like aphids and treat promptly.
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.
⚠️ Common Problems & Solutions — Plant Care Comparison
Alyssum
Old Man's Beard
❓ Frequently Asked Questions — Comparing These Plants
Alyssum
What are the light requirements for Alyssum?
Alyssum prefers full sun, requiring at least 6 hours of direct sunlight each day to thrive and produce abundant blooms. However, in hotter climates, it benefits from some afternoon shade to prevent scorching of the delicate flowers and foliage. Insufficient light can lead to leggy growth, reduced flowering, and pale foliage.
How do I care for Alyssum?
Alyssum thrives in full sun to partial shade. Aim for at least 6 hours of sunlight daily for optimal blooming. Plant in well-draining soil with a slightly acidic to neutral pH (6.0-7.0). Water regularly, allowing the soil to dry slightly between waterings. Avoid overwatering, as this can lead to root rot. Fertilize every 2-3 weeks during the growing season with a balanced liquid fertilizer, focusing on formulas that promote blooming.
How do I propagate Alyssum?
Alyssum can be propagated through seeds, stem cuttings, and division. For stem cuttings, take 4-6 inch cuttings from healthy stems, remove the lower leaves, and dip the cut end in rooting hormone. Plant the cuttings in moist potting mix and keep them in a humid environment until rooted.
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 9, 2026 — Plant care data reviewed and verified by our editorial team.