Monkey Grass vs Physostegia 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.
Physostegia
Physostegia virginiana
Physostegia virginiana, commonly known as Obedient Plant, is a herbaceous perennial native to North America. It features upright, square stems and lance-shaped, toothed leaves. The plant is known for its unique flowers that bloom in late summer and fall, forming dense spikes of tubular, pink, lavender, or white blossoms. The common name comes from the fact that if you gently push a flower to one side, it will often stay in that position. It is primarily an outdoor plant, valued for its late-season blooms and ability to attract pollinators. It can be challenging to grow indoors due to its high light requirements and tendency to spread.
Quick Plant Comparison
| Feature | Monkey Grass | Physostegia |
|---|---|---|
| Light | Full sun to partial shade outdoors. Requires very bright, direct light if attempted indoors. | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering. |
| 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. | Every 7-10 days outdoors, less frequently if in partial shade or cooler conditions. |
| Humidity | 40-60% | 30-50% |
| Temperature | 15-27°C | 18-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate; Can Spread Via Rhizomes. | Fast |
| Max Height | Outdoors: 30-45 cm. Indoors (unlikely to thrive): 20-30cm | Indoors: Rarely exceeds 60 cm (2 feet) and is unlikely to thrive. Outdoors: 60-120 cm (2-4 feet) |
| Pet Safety | ❌ Toxic To Pets | ✅ Safe |
| Soil | Well-draining soil; sandy loam is ideal. Avoid heavy clay soils. | Well-drained soil, loamy or sandy soil is best. Amend heavy clay soils with organic matter. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 10 minutes weekly (mostly weeding around the plant) | Outdoors: 15-30 minutes weekly, including watering, weeding, and pruning. Indoors: 30-45 minutes weekly, including watering, fertilizing, and monitoring for pests and diseases. |
🔬 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. |
Physostegia
| Scientific Name | Physostegia virginiana |
|---|---|
| Family | Lamiaceae |
| Native To | Eastern and Central North America |
| Also Known As | Obedient Plant, False Dragonhead |
| Leaves | Lance-shaped, toothed leaves that are typically 5-15 cm (2-6 inches) long. The leaves are arranged oppositely along the stems and are a medium green color. |
| Flowers | Flowers bloom in late summer and fall, forming dense spikes of tubular, pink, lavender, or white blossoms. Rarely flowers indoors unless provided with intense supplemental lighting. |
📏 Size & Growth — Plant Comparison
Monkey Grass
Physostegia
🌱 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.
Physostegia
Methods: Division, Seed, Stem cuttings
Difficulty: Easy
Tips: Divide rhizomes in spring or fall. Take stem cuttings in late spring or early summer. Sow seeds in spring or fall.
✨ 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
Physostegia
The 'obedient' nature of the flowers, where they stay in place when gently moved, is a unique characteristic. It also blooms later in the season than many other perennials, providing color when other plants are fading.
- ✓ Attracts pollinators to your garden.
- ✓ Provides late-season color.
- ✓ Easy to propagate and share with friends.
- ✓ Adds a unique texture and form to the landscape.
- ✓ Supports local ecosystems by providing food and habitat for wildlife.
- 🐾 Pet Safe
📅 Maintenance Schedule — Plant Care Comparison
Monkey Grass
Physostegia
🌞 Light Requirements
Monkey Grass
Full sun to partial shade outdoors. Requires very bright, direct light if attempted indoors.
Low light tolerant: ❌ No
Physostegia
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.
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.
Physostegia
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Signs of underwatering include wilting leaves and dry soil. Signs of overwatering include yellowing leaves and soggy soil.
🌡️ Temperature & Humidity
Monkey Grass
Temperature: 15-27°C
Humidity: 40-60%
Physostegia
Temperature: 18-27°C
Humidity: 30-50%
🤔 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.
Physostegia
Physostegia virginianaGardeners looking for late-season blooms and a plant that attracts pollinators in an outdoor setting.
✅ Choose This Plant If...
- You want a plant that attracts butterflies and hummingbirds to your garden.
- You need a late-season bloomer to extend your garden's color.
- You have a sunny spot in your garden where it can thrive.
- You enjoy the unique 'obedient' characteristic of the flowers.
- You want a plant that is relatively easy to propagate.
❌ Skip This Plant If...
- You have limited sunlight indoors, as it requires full sun to thrive.
- You don't want a plant that spreads aggressively.
- You are looking for a low-maintenance indoor plant.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Monkey Grass has moderate; can spread via rhizomes. growth, while Physostegia grows fast.
💡 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.
Physostegia Care Tips
Physostegia virginiana is primarily an outdoor plant that requires full sun and well-drained soil. It is challenging to grow indoors due to its high light requirements and aggressive spreading habit. Indoor cultivation requires very bright light, careful watering, and frequent repotting to manage its growth.
- Plant in well-drained soil to prevent root rot.
- Provide full sun for optimal flowering.
- Divide plants every 2-3 years to control spread and rejuvenate growth.
- Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
- Deadhead spent flowers to encourage further blooming.
⚠️ Common Problems & Solutions — Plant Care Comparison
Monkey Grass
Physostegia
❓ 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.
Physostegia
What are the light requirements for Physostegia?
Physostegia prefers full sun, which translates to at least six hours of direct sunlight per day. In hotter climates, some afternoon shade can be beneficial to prevent scorching. Insufficient light can lead to leggy growth and reduced flowering. When growing Physostegia indoors (less common), place it near a sunny window, such as a south-facing exposure. Rotate the plant regularly to ensure even light distribution. Be mindful of the intensity of the sunlight, especially during peak summer months, as too much direct sun can also damage the foliage. Observe the plant’s growth and adjust its position accordingly to provide optimal light conditions.
How do I care for Physostegia?
Physostegia thrives in full sun to partial shade, requiring at least six hours of sunlight daily for optimal blooming. Water regularly, especially during dry spells, keeping the soil consistently moist but not waterlogged. Well-draining soil is essential to prevent root rot. Fertilize in early spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage continuous blooming throughout the summer. Physostegia can spread aggressively, so consider planting it in a container or using barriers to control its growth. Divide clumps every few years to maintain vigor and prevent overcrowding. Monitor for common pests like aphids and spider mites, and treat as needed.
How do I propagate Physostegia?
Physostegia can be easily propagated through division. In early spring or fall, carefully dig up the plant and divide the root clump into smaller sections, ensuring each section has healthy roots and shoots. Replant the divisions in well-draining soil. Stem cuttings can also be taken in late spring or early summer. Take 4-6 inch cuttings from new growth, remove the lower leaves, and dip the cut end in rooting hormone. Plant the cuttings in a moist potting mix and keep them humid until rooted. Physostegia does not produce keikis.
Last updated: April 18, 2026 — Plant care data reviewed and verified by our editorial team.