Licorice Plant vs Penstemon Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Licorice Plant
Glycyrrhiza glabra
Glycyrrhiza glabra, commonly known as licorice, is a perennial herbaceous plant that grows to about 1 meter (3 feet) tall. It features pinnate leaves and pea-like flowers, typically purple to pale blue. The plant is primarily cultivated for its rhizomes and roots, which contain glycyrrhizin, a compound responsible for its characteristic sweet flavor. Licorice is mainly grown outdoors in well-drained soil and full sun. While it can be attempted indoors, it's challenging to replicate its ideal growing conditions, and it may not thrive.
Penstemon
Penstemon spp.
Penstemon is a diverse genus of flowering plants, primarily herbaceous perennials, known for their vibrant, tubular flowers. They range in size from a few inches to several feet tall, with varying growth habits from upright to spreading. The flowers come in a wide array of colors, including shades of blue, purple, pink, red, and white, attracting pollinators like bees and hummingbirds. Penstemons are primarily grown outdoors in gardens and naturalized areas for their showy blooms, drought tolerance, and ability to attract wildlife. They are not typically grown indoors due to their high light requirements and need for specific environmental conditions.
Quick Plant Comparison
| Feature | Licorice Plant | Penstemon |
|---|---|---|
| Light | Full sun (at least 6-8 hours of direct sunlight daily) | Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering. |
| Watering | Every 5-7 days during the growing season, less frequently in winter. | Every 1-2 weeks, depending on weather and soil drainage. |
| Humidity | 40-60% | 30-50% |
| Temperature | 15-27°C | 15-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Moderate |
| Max Height | 0.5-1 meter (indoors, likely smaller) | 0.3-1.2 meters (outdoors) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-drained loamy soil | Well-draining soil, such as a sandy or gravelly loam. Avoid heavy clay soils. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly (primarily for watering, weeding, and pest control). | 15 minutes weekly (outdoor) |
🔬 Botanical Information — Comparing These Plants
Licorice Plant
| Scientific Name | Glycyrrhiza glabra |
|---|---|
| Family | Fabaceae |
| Native To | Southern Europe and parts of Asia |
| Also Known As | Licorice, Liquorice |
| Leaves | The leaves are pinnately compound, typically consisting of 9-17 leaflets. Each leaflet is oval to lance-shaped, with a smooth margin and a slightly sticky texture. The leaves are generally green in color. |
| Flowers | Licorice produces pea-like flowers that are typically purple to pale blue. Flowering usually occurs in the summer months. It is unlikely to flower indoors due to insufficient light. |
Penstemon
| Scientific Name | Penstemon spp. |
|---|---|
| Family | Plantaginaceae |
| Native To | North America, particularly western North America |
| Also Known As | Beardtongue, Penstemon |
| Leaves | Leaves are typically lance-shaped to oval, arranged oppositely along the stem. They can be smooth or slightly hairy, and vary in color from green to bluish-green. Leaf size varies depending on the species. |
| Flowers | Penstemon rarely flowers indoors due to insufficient light. Outdoors, they produce showy, tubular flowers in a wide range of colors, including blue, purple, pink, red, and white. Flowers are arranged in clusters or spikes at the ends of stems. |
📏 Size & Growth — Plant Comparison
Licorice Plant
Penstemon
🌱 Propagation — Comparing Plant Growth
Licorice Plant
Methods: Seed, Rhizome division, Root cuttings
Difficulty: Moderate
Tips: For rhizome division, separate rhizomes in early spring and plant them in well-drained soil. Root cuttings should be taken in late fall or early winter and planted horizontally.
Penstemon
Methods: Seed, stem cuttings, division
Difficulty: Moderate
Tips: For stem cuttings, take cuttings in late spring or early summer and root them in well-draining soil. Division can be done in early spring or fall. Seeds can be sown in spring or fall.
✨ Benefits & Features — Comparing Plant Value
Licorice Plant
The roots of Glycyrrhiza glabra contain glycyrrhizin, a compound that is significantly sweeter than sugar. This plant has a long history of use in both culinary and traditional medicine.
- ✓ Provides a unique flavoring agent for culinary uses.
- ✓ Has potential medicinal properties (consult a healthcare professional).
- ✓ Adds visual interest to a garden with its foliage and flowers.
- ✓ Can be a rewarding challenge for experienced gardeners.
- ✓ Supports biodiversity in a garden ecosystem.
- ⚠️ Toxic to pets
Penstemon
Penstemon's tubular flowers are specifically adapted for pollination by bees and hummingbirds, showcasing a co-evolutionary relationship. The sterile stamen, or beardtongue, is a distinctive feature of the genus. Many species are native to specific regions and play important roles in local ecosystems.
- ✓ Attracts pollinators, supporting local ecosystems.
- ✓ Adds vibrant color and visual interest to gardens.
- ✓ Drought-tolerant, reducing water consumption.
- ✓ Relatively deer resistant, protecting from browsing.
- ✓ Provides a source of nectar for hummingbirds and bees.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Licorice Plant
Penstemon
🌞 Light Requirements
Licorice Plant
Full sun (at least 6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
Penstemon
Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.
Low light tolerant: ❌ No
💧 Watering Needs
Licorice Plant
Water deeply when the top inch of soil feels dry to the touch. Avoid overwatering, which can lead to root rot. Signs of overwatering include yellowing leaves and a musty smell. Underwatering is indicated by wilting and dry, crispy leaves.
Penstemon
Water deeply when the top inch of soil is dry. Avoid overwatering, as Penstemons are susceptible to root rot. Allow the soil to dry out slightly between waterings. Signs of overwatering include yellowing leaves and wilting, while underwatering can cause leaf drop and stunted growth.
🌡️ Temperature & Humidity
Licorice Plant
Temperature: 15-27°C
Humidity: 40-60%
Penstemon
Temperature: 15-27°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Licorice Plant
Glycyrrhiza glabraExperienced gardeners who want to grow licorice outdoors for its roots, understanding its toxicity to pets.
✅ Choose This Plant If...
- You have a sunny outdoor garden space.
- You are interested in harvesting licorice root for culinary or medicinal purposes.
- You are an experienced gardener looking for a unique plant to grow.
- You understand the plant's toxicity to pets and can keep it away from them.
- You are prepared to provide the specific care this plant needs to thrive.
❌ Skip This Plant If...
- You have pets that might ingest the plant.
- You lack a sunny outdoor space.
- You are a beginner gardener.
- You are looking for a low-maintenance indoor plant.
- You are not prepared to manage the plant's potential for rhizomatous spread.
Penstemon
Penstemon spp.Gardeners looking for drought-tolerant, pollinator-attracting plants for sunny locations.
✅ Choose This Plant If...
- You want to attract hummingbirds and bees to your garden.
- You need a drought-tolerant plant for a sunny location.
- You desire a long-blooming perennial with vibrant colors.
- You want a plant that is relatively deer resistant.
- You are looking for a native plant to support local ecosystems.
❌ Skip This Plant If...
- You have pets that may ingest the plant.
- You cannot provide at least 6 hours of direct sunlight daily.
- You live in a humid climate with poorly draining soil.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.
💡 Pro Tips For Comparing These Plants
Licorice Plant Care Tips
Licorice is primarily an outdoor plant and requires full sun and well-drained soil. Growing it indoors is challenging due to its high light requirements and potential for rhizomatous spread. It also poses a toxicity risk to pets. Indoor cultivation requires careful attention to light, watering, and potential toxicity.
- Provide well-drained soil to prevent root rot.
- Ensure at least 6-8 hours of direct sunlight daily.
- Monitor for pests like aphids and spider mites.
- Harvest licorice roots in the fall after 3-4 years of growth.
- Be mindful of its potential for rhizomatous spread and contain it if necessary.
Penstemon Care Tips
Penstemon is primarily an outdoor plant that requires full sun and well-draining soil. It is not well-suited for indoor growing due to its high light requirements and need for specific environmental conditions. Indoor attempts are likely to fail without supplemental lighting and careful monitoring of soil moisture.
- Plant in well-draining soil to prevent root rot.
- Provide at least 6 hours of direct sunlight daily for optimal flowering.
- Deadhead spent flowers regularly to encourage more blooms.
- Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
- Apply a balanced fertilizer in early spring before new growth begins.
⚠️ Common Problems & Solutions — Plant Care Comparison
Licorice Plant
Penstemon
❓ Frequently Asked Questions — Comparing These Plants
Licorice Plant
What are the light requirements for Licorice Plant?
Licorice Plant thrives in bright, indirect light. Too much direct sunlight can scorch the leaves, while insufficient light can lead to leggy growth and faded foliage color. An east-facing window is often ideal, providing gentle morning sun. A south- or west-facing window can also work, but be sure to filter the light with sheer curtains or blinds, especially during the hottest part of the day.
How do I care for Licorice Plant?
Licorice Plant thrives in well-draining soil. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain. Provide bright, indirect light for optimal growth, though it can tolerate some direct sun, especially in the morning. These plants prefer moderate temperatures, ideally between 60-75°F (15-24°C). Fertilize lightly every 4-6 weeks during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength.
How do I propagate Licorice Plant?
Licorice Plant is easily propagated through stem cuttings and layering. For stem cuttings, take a 4-6 inch cutting from a healthy stem, removing the lower leaves. Dip the cut end in rooting hormone and plant it in moist, well-draining potting mix. Cover with a plastic bag or humidity dome to maintain moisture. Keep in bright, indirect light until roots develop, usually within 2-4 weeks.
Penstemon
What are the light requirements for Penstemon?
Penstemon requires at least six hours of direct sunlight per day to thrive and produce abundant blooms. A location with full sun exposure is ideal. If growing Penstemon indoors, place it near a sunny window, preferably a south-facing one. Insufficient light can result in leggy growth, reduced flowering, and pale foliage. In hot climates, some afternoon shade may be beneficial to prevent scorching. Rotate the plant regularly to ensure even light exposure on all sides. Consider using grow lights to supplement natural light during the darker months of the year, especially for indoor plants.
How do I care for Penstemon?
Penstemon thrives in well-draining soil and prefers full sun, although some varieties can tolerate partial shade. Water regularly during the first growing season to establish a strong root system, then reduce watering frequency as the plant matures. Avoid overwatering, as this can lead to root rot. Fertilize in early spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage continuous blooming. Prune back in late fall or early spring to maintain shape and remove any dead or damaged growth. Provide good air circulation to prevent fungal diseases. Mulch around the base of the plant to conserve moisture and suppress weeds. Penstemon is generally hardy but may benefit from winter protection in colder climates.
How do I propagate Penstemon?
Penstemon can be propagated by division, stem cuttings, and seeds.
Last updated: May 4, 2026 — Plant care data reviewed and verified by our editorial team.