Bachelor's Button vs Princess Tree Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Bachelor's Button

Bachelor's Button

Centaurea cyanus

VS
Princess Tree

Princess Tree

Paulownia tomentosa

Bachelor's Button

Bachelor's Button

Centaurea cyanus

Bachelor's Button, or Cornflower, is an annual plant typically grown outdoors for its vibrant blue, pink, white, or purple flowers. It features slender, grey-green leaves and an upright growth habit, reaching heights of 1 to 3 feet. While admired for its ornamental value and use in cut flower arrangements, it is primarily an outdoor plant that thrives in full sun. People grow it for its attractive flowers that attract pollinators and its ease of cultivation in gardens and fields.

Asteraceae Europe, though naturalized in many parts of the world
✨ Features: Attracts pollinators such as bees and butterflies.
📖 Read Complete Bachelor's Button Guide
Princess Tree

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.

Paulowniaceae Central and Western China
✨ Features: Rapid growth, large leaves, fragrant spring flowers, persistent seed capsules.
📖 Read Complete Princess Tree Guide

Quick Plant Comparison

Feature Bachelor's Button Princess Tree
Light Full sun (at least 6 hours of direct sunlight daily) Full sun
Watering Every 7-10 days, 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 15-24°C 15-27°C
Care Level Expert Expert
Growth Rate Fast Fast
Max Height Not typically grown indoors; outdoors 30-90 cm Not applicable - unsuitable for indoor growing. Outdoors: 9-18 meters
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, sandy or loamy soil is ideal Well-draining soil, adaptable to various soil types including clay, loam, and sand.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 5 minutes weekly (deadheading, watering) 1-2 hours per month, primarily for pruning and managing spread.

🔬 Botanical Information — Comparing These Plants

Bachelor's Button

Scientific Name Centaurea cyanus
Family Asteraceae
Native To Europe, though naturalized in many parts of the world
Also Known As Cornflower, Bluebottle, Boutonniere Flower
Leaves The leaves are slender, lance-shaped, and grey-green in color. They are typically 2-5 cm long and have a slightly hairy texture.
Flowers It rarely flowers indoors. Outdoors, it produces vibrant blue, pink, white, or purple flowers. The flowers are typically 2-4 cm in diameter and have a fringed appearance.

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

Bachelor's Button

Height Not typically grown indoors; outdoors 30-90 cm
Spread Outdoors 30-60 cm
Growth Rate Fast
Growth Pattern Upright, branching annual plant. It grows from seed to flower in a single season, reaching a height of 1 to 3 feet. It does not spread aggressively but can self-seed readily.

Princess Tree

Height Not applicable - unsuitable for indoor growing. Outdoors: 9-18 meters
Spread Not applicable - unsuitable for indoor growing. Outdoors: 9-12 meters
Growth Rate Fast
Growth Pattern Upright, spreading tree with a rounded crown. It grows rapidly, often adding several feet of height per year. It can also spread through root suckers.

🌱 Propagation — Comparing Plant Growth

Bachelor's Button

Methods: Seed

Difficulty: Easy

Tips: Sow seeds directly into the garden in early spring or fall. Seeds need light to germinate, so do not cover them too 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

Bachelor's Button

Bachelor's Button is known for its vibrant blue flowers, although other colors are available. It is an annual plant that readily self-seeds, making it a reliable addition to the garden year after year. It is also attractive to pollinators, making it a valuable plant for supporting local ecosystems.

  • ✓ Attracts pollinators to the garden
  • ✓ Provides beautiful cut flowers
  • ✓ Edible flowers for culinary use
  • ✓ Adds vibrant color to outdoor spaces
  • ✓ Easy to grow from seed outdoors
  • ⚠️ 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

Bachelor's Button

Repotting Not applicable as it is an annual plant typically grown directly in the ground.
Pruning Deadhead spent flowers to encourage more blooms and prevent seed formation if desired.
Fertilizing Balanced liquid fertilizer diluted to half strength, applied every 4-6 weeks during the growing season
Seasonal Care In spring, sow seeds directly into the garden. In summer, provide regular watering and deadhead spent flowers to encourage more blooms. In fall, collect seeds for next year's planting. In winter, the plant dies back as it is an annual.

Princess Tree

Repotting Not applicable - unsuitable for indoor growing.
Pruning Prune in late winter or early spring to remove dead or damaged branches and shape the tree.
Fertilizing Use a balanced fertilizer (10-10-10) in early spring to promote growth. Avoid over-fertilizing.
Seasonal Care In spring, fertilize and monitor for pests. In summer, ensure adequate watering. In fall, collect seeds if desired. In winter, protect young trees from frost damage.

🌞 Light Requirements

Bachelor's Button

Full sun (at least 6 hours of direct sunlight daily)

Low light tolerant: ❌ No

Princess Tree

Full sun

Low light tolerant: ❌ No

💧 Watering Needs

Bachelor's Button

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. In well-draining soil, water deeply but infrequently. Signs of underwatering include wilting and dry, crispy leaves. Overwatering symptoms include 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

Bachelor's Button

Temperature: 15-24°C

Humidity: 30-50%

Princess Tree

Temperature: 15-27°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Bachelor's Button

Bachelor's Button

Centaurea cyanus
Care: Expert Time: 5 minutes weekly (deadheading, watering) Beginner: No

Gardeners who want to attract pollinators to their outdoor gardens.

✅ Choose This Plant If...

  • You want to attract pollinators to your garden.
  • You enjoy cut flowers and want to grow your own.
  • You want a low-maintenance annual for a sunny spot.
  • You want to add a splash of vibrant color to your garden.
  • You enjoy edible flowers in salads or teas.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You don't have a sunny outdoor space.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoor garden, flower bed, or meadow in full sun
🎨 Style: Cottage garden, wildflower meadow, traditional
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Centaurea cyanus is toxic to dogs, cats, and horses. Symptoms include dermatitis and gastrointestinal upset. All parts of the plant are considered toxic.
Princess Tree

Princess Tree

Paulownia tomentosa
Care: Expert Time: 1-2 hours per month, primarily for pruning and managing spread. Beginner: No

Landowners 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.
📍 Ideal Location: Large outdoor space with full sun and well-draining soil.
🎨 Style: Natural, Traditional, Cottage
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Paulownia tomentosa is toxic to horses. The toxic principle is unknown, but symptoms include blistering of the mouth and skin.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

☀️

Bachelor's Button needs full sun (at least 6 hours of direct sunlight daily), while Princess Tree prefers full sun.

💡 Pro Tips For Comparing These Plants

Bachelor's Button Care Tips

Bachelor's Button is primarily an outdoor plant and is challenging to grow indoors due to its high light requirements. It needs full sun and well-draining soil. Indoor cultivation requires supplemental lighting and careful watering to prevent fungal diseases. It is best suited for outdoor gardens.

  • Sow seeds directly in the garden in early spring or fall.
  • Choose a location with full sun and well-draining soil.
  • Water regularly, especially during dry periods.
  • Deadhead spent flowers to encourage more blooms.
  • Protect from strong winds.
❄️ Winter: As an annual, Bachelor's Button dies back in the winter. Collect seeds for planting in the spring.
☀️ Summer: Provide regular watering during hot, dry periods. Deadhead spent flowers to encourage more blooms. Protect from strong winds.

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.
❄️ Winter: Protect young trees from frost damage by wrapping the trunk with burlap. Reduce watering during the dormant season.
☀️ Summer: Ensure adequate watering during dry periods. Monitor for pests and diseases. Provide shade for young trees during the hottest part of the day.

⚠️ Common Problems & Solutions — Plant Care Comparison

Bachelor's Button

Common Issues: Powdery mildew, aphids, root rot, lack of flowering
Solutions: For powdery mildew, improve air circulation and apply a fungicide. Control aphids with insecticidal soap. Prevent root rot by ensuring well-draining soil and avoiding overwatering. Provide sufficient sunlight to encourage flowering.

Princess Tree

Common Issues: Invasive spread, susceptibility to wind damage, root rot in poorly drained soils, leaf spot diseases.
Solutions: Control spread by removing seedlings and suckers. Provide wind protection. Ensure proper drainage. Treat leaf spot with appropriate fungicide.

❓ Frequently Asked Questions — Comparing These Plants

Bachelor's Button

What are the light requirements for Bachelor's Button?

Bachelor’s Buttons require at least 6-8 hours of direct sunlight each day to thrive. Insufficient light can result in leggy growth, fewer blooms, and pale foliage. Choose a location in your garden that receives full sun throughout the day. If growing indoors, place them near a south-facing window where they can receive ample sunlight.

How do I care for Bachelor's Button?

Bachelor’s Buttons thrive in full sun and well-drained soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize with a balanced, slow-release fertilizer in spring to encourage abundant blooms. Deadhead spent flowers regularly to promote continuous flowering throughout the season. These plants are relatively cold-hardy but may benefit from a layer of mulch in colder climates.

How do I propagate Bachelor's Button?

Bachelor’s Buttons are primarily propagated by seed. Allow some flowers to go to seed and collect the seeds once they are dry. Sow the seeds in spring or fall in well-drained soil. Keep the soil consistently moist until germination. Thin seedlings to ensure proper spacing.

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: April 25, 2026 — Plant care data reviewed and verified by our editorial team.