Monkey Grass 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.
Monkey Grass
Liriope muscari
Liriope muscari, commonly known as lilyturf or monkey grass, is a grass-like perennial often used as a ground cover or border plant. It features clumps of arching, strap-like, dark green leaves. While it resembles grass, it's not a true grass. It produces spikes of small, lavender to purple flowers in late summer, followed by blackish berries. Primarily an outdoor plant, it's valued for its low maintenance, drought tolerance, and ability to suppress weeds. It's rarely grown indoors due to its need for bright light and outdoor conditions.
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 | Monkey Grass | Old Man's Beard |
|---|---|---|
| Light | Full sun to partial shade outdoors. Requires very bright, direct light if attempted indoors. | Bright, indirect light outdoors. Full sun can scorch it in dry conditions. |
| Watering | Outdoors: Every 7-14 days, depending on rainfall and temperature. Indoors (if attempted): Every 7-10 days, allowing the soil to dry slightly between waterings. | Dependent on environmental humidity; mist when dry |
| Humidity | 40-60% | 60-90% |
| Temperature | 15-27°C | 5-25°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate; Can Spread Via Rhizomes. | Slow |
| Max Height | Outdoors: 30-45 cm. Indoors (unlikely to thrive): 20-30cm | Variable, up to several feet long depending on the species and environment. |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining soil; sandy loam is ideal. Avoid heavy clay soils. | Does not grow in soil. Attaches to tree bark or other surfaces. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 10 minutes weekly (mostly weeding around the plant) | 5 minutes weekly (for misting if needed). |
🔬 Botanical Information — Comparing These Plants
Monkey Grass
| Scientific Name | Liriope muscari |
|---|---|
| Family | Asparagaceae |
| Native To | East Asia (China, Japan, Korea) |
| Also Known As | Lilyturf, Border Grass |
| Leaves | Strap-like, linear leaves, typically dark green in color. Can be variegated in some cultivars. Leaves are typically 20-40 cm long and 1-2 cm wide. |
| Flowers | Produces spikes of small, lavender to purple flowers in late summer. Flowering is rare and less pronounced when grown 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
Monkey Grass
Old Man's Beard
🌱 Propagation — Comparing Plant Growth
Monkey Grass
Methods: Division, Seed
Difficulty: Easy
Tips: Division is best done in spring or fall. Dig up a clump and separate the rhizomes, ensuring each division has roots and leaves. Plant the divisions in well-draining soil.
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
Monkey Grass
It is a grass-like perennial that is not a true grass. It produces attractive flower spikes and berries. It is drought-tolerant and relatively low-maintenance once established.
- ✓ Erosion control on slopes.
- ✓ Low maintenance ground cover.
- ✓ Weed suppression in garden beds.
- ✓ Drought tolerance once established.
- ✓ Provides visual interest with its foliage and flowers.
- ⚠️ 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
Monkey Grass
Old Man's Beard
🌞 Light Requirements
Monkey Grass
Full sun to partial shade outdoors. Requires very bright, direct light if attempted indoors.
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
Monkey Grass
Water thoroughly when the top inch of soil is dry. Overwatering can lead to root rot, especially in poorly draining soil. Underwatering will cause the leaves to brown and droop. Ensure good drainage.
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
Monkey Grass
Temperature: 15-27°C
Humidity: 40-60%
Old Man's Beard
Temperature: 5-25°C
Humidity: 60-90%
🤔 Which Plant Is Right For You?
Monkey Grass
Liriope muscariGardeners seeking a low-maintenance ground cover or border plant in outdoor landscapes.
✅ Choose This Plant If...
- You need a low-maintenance ground cover for your garden.
- You want to control erosion on a slope.
- You need a plant that is drought-tolerant once established.
- You want to suppress weeds in your garden beds.
- You need a plant that tolerates partial shade.
❌ Skip This Plant If...
- You have pets that might ingest it, as it is toxic.
- You are looking for an easy indoor plant, as it is challenging to grow indoors.
- You have limited space, as it can spread aggressively.
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
Monkey Grass has moderate; can spread via rhizomes. growth, while Old Man's Beard grows slow.
💡 Pro Tips For Comparing These Plants
Monkey Grass Care Tips
Liriope muscari is primarily an outdoor plant. Indoor cultivation is challenging due to its high light requirements and need for well-draining soil. It can be aggressive, spreading via rhizomes. Toxicity to pets is a significant concern.
- Plant in well-draining soil to prevent root rot.
- Water deeply but infrequently, allowing the soil to dry slightly between waterings.
- Fertilize in spring with a slow-release fertilizer.
- Divide clumps every few years to control spread and rejuvenate the plant.
- Monitor for pests and diseases, 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
Monkey Grass
Old Man's Beard
❓ Frequently Asked Questions — Comparing These Plants
Monkey Grass
What are the light requirements for Monkey Grass?
Monkey Grass thrives in bright, indirect light. While it can tolerate some shade, too little light can lead to leggy growth and reduced vibrancy. Avoid direct sunlight, especially during the hottest parts of the day, as it can scorch the leaves. East-facing windows are ideal, providing gentle morning light. North-facing windows can also work if the light is sufficient. If you notice the leaves fading or stretching towards the light source, move the plant to a brighter location. Consider using grow lights if natural light is insufficient, especially during winter months. Rotate the plant regularly to ensure even light exposure on all sides.
How do I care for Monkey Grass?
Monkey Grass is relatively easy to care for. Provide bright, indirect light for optimal growth. Water regularly, keeping the soil consistently moist but not waterlogged. Ensure good drainage to prevent root rot. Fertilize lightly during the growing season (spring and summer) with a balanced liquid fertilizer. Prune away any dead or damaged foliage to maintain its appearance and encourage new growth. Monkey Grass prefers temperatures between 60-75°F (15-24°C) and appreciates high humidity. Mist the foliage regularly or use a humidifier to increase humidity levels, especially in dry environments. Repot every 2-3 years as needed, using a well-draining potting mix.
How do I propagate Monkey Grass?
Monkey Grass can be propagated through division, stem cuttings, and air layering.
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: April 20, 2026 — Plant care data reviewed and verified by our editorial team.