Mullein vs Princess Tree Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Mullein
Verbascum thapsus
Great Mullein is a biennial plant characterized by a rosette of large, velvety, gray-green leaves in its first year. In the second year, it sends up a tall, erect flower stalk that can reach up to 2 meters in height. This stalk is densely covered with small, yellow flowers that bloom sequentially from the bottom upwards. It's primarily an outdoor plant, grown for its striking architectural form and traditional medicinal uses. Indoor cultivation is extremely challenging due to its need for intense sunlight and space.
Princess Tree
Paulownia tomentosa
Paulownia tomentosa, the Princess Tree, is a deciduous tree known for its rapid growth and large, heart-shaped leaves. It can reach heights of 30-60 feet. In spring, it produces fragrant, pale purple flowers in panicles before the leaves emerge. These are followed by persistent seed capsules. While admired for its ornamental value, it's considered invasive in many regions due to its prolific seed production and ability to resprout from roots. It is primarily an outdoor tree and not suitable for indoor cultivation.
Quick Plant Comparison
| Feature | Mullein | Princess Tree |
|---|---|---|
| Light | Full sun (at least 6-8 hours of direct sunlight daily) | Full sun |
| Watering | Every 2-4 weeks, depending on weather and soil drainage | Once or twice a week during the growing season, less frequently during dormancy. |
| Humidity | 30-50% | 30-50% |
| Temperature | 10-30°C | 15-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate To Fast | Fast |
| Max Height | 1-2 meters (outdoor) | Not applicable - unsuitable for indoor growing. Outdoors: 9-18 meters |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining, sandy or gravelly soil. Mullein tolerates poor soil conditions. | Well-draining soil, adaptable to various soil types including clay, loam, and sand. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 5 minutes weekly (weeding, deadheading) | 1-2 hours per month, primarily for pruning and managing spread. |
🔬 Botanical Information — Comparing These Plants
Mullein
| Scientific Name | Verbascum thapsus |
|---|---|
| Family | Scrophulariaceae |
| Native To | Europe, Asia, North Africa; naturalized in the Americas and Australia |
| Also Known As | Great Mullein, Common Mullein, Woolly Mullein, Aaron's Rod |
| Leaves | The leaves of Mullein are large, oblong to lance-shaped, and covered in dense, woolly hairs, giving them a soft, velvety texture and a gray-green color. The basal leaves can be up to 30 cm long, while the stem leaves are smaller and alternate along the flower stalk. |
| Flowers | Mullein produces numerous small, yellow flowers that are densely packed along the upper portion of the flower stalk. The flowers bloom sequentially from the bottom upwards over a long period in summer. |
Princess Tree
| Scientific Name | Paulownia tomentosa |
|---|---|
| Family | Paulowniaceae |
| Native To | Central and Western China |
| Also Known As | Princess Tree, Empress Tree, Foxglove Tree |
| Leaves | The leaves are large, heart-shaped (cordate), and can reach up to 12 inches in length. They are typically a medium green color and have a slightly fuzzy texture when young. |
| Flowers | It rarely, if ever, flowers indoors. Outdoors, it produces large panicles of fragrant, pale purple flowers in spring before the leaves emerge. |
📏 Size & Growth — Plant Comparison
Mullein
Princess Tree
🌱 Propagation — Comparing Plant Growth
Mullein
Methods: Seed
Difficulty: Easy
Tips: Sow seeds directly into the ground in spring or fall. Mullein seeds require light to germinate, so do not bury them deeply. Keep the soil moist until germination occurs.
Princess Tree
Methods: Seeds, root cuttings, stem cuttings
Difficulty: Moderate
Tips: For seeds, cold stratify for several weeks before sowing. Root cuttings should be taken in late winter. Stem cuttings can be taken in summer.
✨ Benefits & Features — Comparing Plant Value
Mullein
Mullein's velvety leaves and tall flower stalk make it a striking addition to any garden. Its drought tolerance and ability to thrive in poor soil make it a low-maintenance choice for challenging locations.
- ✓ Attracts pollinators
- ✓ Drought-tolerant
- ✓ Unique architectural form
- ✓ Traditional medicinal uses
- ✓ Low maintenance
- ⚠️ Toxic to pets
Princess Tree
Its rapid growth rate and large leaves distinguish it from many other trees. The fragrant spring flowers are also a notable feature. However, its invasive nature is a significant consideration.
- ✓ Provides shade in large outdoor spaces.
- ✓ Offers fragrant spring flowers.
- ✓ Attracts pollinators.
- ✓ Provides habitat for wildlife.
- ✓ Can be used for erosion control on slopes.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Mullein
Princess Tree
🌞 Light Requirements
Mullein
Full sun (at least 6-8 hours of direct sunlight daily)
Low light tolerant: ❌ No
Princess Tree
Full sun
Low light tolerant: ❌ No
💧 Watering Needs
Mullein
Water deeply when the soil is dry to the touch. Mullein is drought-tolerant once established. Overwatering can lead to root rot. Allow the soil to dry out completely between waterings. Signs of underwatering include wilting and drooping leaves; overwatering presents as yellowing leaves and a soggy soil.
Princess Tree
Water deeply when the topsoil feels dry to the touch, especially during the growing season. Avoid overwatering, which can lead to root rot. Reduce watering in the dormant season. Signs of underwatering include wilting leaves; overwatering includes yellowing leaves and soggy soil.
🌡️ Temperature & Humidity
Mullein
Temperature: 10-30°C
Humidity: 30-50%
Princess Tree
Temperature: 15-27°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Mullein
Verbascum thapsusGardeners looking for a striking, drought-tolerant plant for a sunny location.
✅ Choose This Plant If...
- You want a drought-tolerant plant for a sunny garden.
- You are interested in traditional medicinal herbs.
- You want to attract pollinators to your garden.
- You appreciate plants with a unique architectural form.
- You have poor soil conditions that other plants struggle in.
❌ Skip This Plant If...
- You have limited sunlight available.
- You are looking for an easy-to-grow indoor plant.
- You have pets that might ingest the plant.
Princess Tree
Paulownia tomentosaLandowners with large properties in non-invasive regions who appreciate fast-growing shade trees with showy spring flowers.
✅ Choose This Plant If...
- You have a large outdoor space and want a fast-growing shade tree.
- You appreciate fragrant spring flowers.
- You are prepared to manage its potentially invasive nature.
- You want a tree that can tolerate a variety of soil conditions.
- You are looking for a tree that provides habitat for wildlife.
❌ Skip This Plant If...
- You have a small garden or limited space.
- You live in a region where it is considered invasive.
- You are not prepared to manage its rapid growth and spread.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Mullein needs full sun (at least 6-8 hours of direct sunlight daily), while Princess Tree prefers full sun.
Mullein has moderate to fast growth, while Princess Tree grows fast.
💡 Pro Tips For Comparing These Plants
Mullein Care Tips
Mullein is an outdoor plant that is extremely difficult to grow indoors due to its high light requirements and large size. It needs full sun and well-draining soil. Indoor cultivation is generally not recommended. It is toxic to pets if ingested.
- Provide full sun for optimal growth.
- Ensure well-draining soil to prevent root rot.
- Avoid overwatering, especially in winter.
- Deadhead spent flowers to encourage continued blooming.
- Protect young plants from frost in their first winter.
Princess Tree Care Tips
Paulownia tomentosa is an outdoor tree that requires full sun and well-draining soil. It is not suitable for indoor cultivation due to its size and light requirements. It is considered invasive in many areas, requiring careful management to prevent its spread.
- Monitor for invasive spread and remove seedlings promptly.
- Prune regularly to maintain shape and remove dead or damaged branches.
- Water deeply during dry periods, especially when young.
- Fertilize in early spring with a balanced fertilizer.
- Protect young trees from strong winds.
⚠️ Common Problems & Solutions — Plant Care Comparison
Mullein
Princess Tree
❓ Frequently Asked Questions — Comparing These Plants
Mullein
What are the light requirements for Mullein?
Mullein thrives in full sun, requiring at least six to eight hours of direct sunlight per day. Insufficient light can result in leggy growth, reduced flowering, and overall weaker plants. When planting Mullein, choose a location that receives unobstructed sunlight throughout the day. South-facing gardens or open fields are ideal. If growing Mullein indoors, place it near a sunny window or supplement with grow lights. Rotate the plant regularly to ensure even light exposure. Monitor the plant for signs of inadequate light, such as stretching towards the light source or pale foliage. Adjust the plant’s position or supplement with artificial lighting as needed to provide the necessary sunlight for healthy growth and abundant flowering.
How do I care for Mullein?
Mullein is generally easy to care for, but specific conditions will encourage optimal growth and flowering. Plant Mullein in well-draining soil, preferably sandy or gravelly, in a location that receives at least six hours of sunlight daily. Water deeply but infrequently, allowing the soil to dry out between waterings. Avoid overwatering, as this can lead to root rot. Fertilize sparingly, if at all, as Mullein thrives in nutrient-poor soil. Deadhead spent flowers to encourage additional blooming. In colder climates, provide winter protection by mulching around the base of the plant. Be mindful of self-seeding, as Mullein can spread readily. Monitor for pests and diseases, although Mullein is generally resistant. Prune back the flower stalk after blooming to maintain a tidy appearance. Ensure good air circulation to prevent fungal issues.
How do I propagate Mullein?
Mullein is most easily propagated by seed. Collect seeds from dried flower stalks in the fall. Direct sow seeds in the spring after the last frost, or start indoors 6-8 weeks before the last frost. Surface sow the seeds as they need light to germinate. Keep the soil moist but not waterlogged. Seedlings should emerge in 14-21 days. Thin seedlings to allow adequate spacing. Mullein can also be propagated by root cuttings in the spring or fall. Dig up a small section of root and replant it in well-draining soil. Keep the soil moist until new growth appears. Division of offsets is possible, but less common. Stem cuttings are not an effective method for Mullein.
Princess Tree
What are the light requirements for Princess Tree?
Princess Tree thrives in bright, indirect light. Insufficient light can lead to leggy growth and reduced leaf size. Place your Princess Tree near a sunny window, ideally facing east or west. If you only have a south-facing window, filter the light with a sheer curtain to prevent scorching. Rotate the plant regularly to ensure even light exposure on all sides. If natural light is limited, consider supplementing with artificial grow lights to provide the necessary light intensity. Pale leaves or slow growth can indicate insufficient light.
How do I care for Princess Tree?
To successfully grow Princess Tree indoors, provide it with bright, indirect light; direct sunlight can scorch the leaves. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels, especially during the winter months when indoor air tends to be drier. Fertilize regularly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Repot the plant every 1-2 years, or when it becomes root-bound, using a well-draining potting mix. Prune as needed to maintain shape and remove any dead or damaged leaves. Monitor for pests such as spider mites and aphids, and treat promptly with insecticidal soap or neem oil. Maintain stable temperatures, avoiding drastic fluctuations.
How do I propagate Princess Tree?
Princess Tree can be propagated through stem cuttings and air layering.
Last updated: May 8, 2026 — Plant care data reviewed and verified by our editorial team.