How to Grow Princess Flower

Wikimedia Commons

Princess Flower

Tibouchina semidecandra

shrub

Princess Flower is a striking tropical to subtropical shrub known for its vibrant purple-blue flowers with prominent stamens and soft, velvety foliage. The plant produces large, showy blooms throughout warm months and can reach 6-10 feet tall in ideal conditions. It's a popular ornamental choice for gardens, containers, and conservatories in warmer climates.

When should you plant Princess Flower in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Princess Flower timeline →

Example Princess Flower timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Princess Flower

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Princess Flower

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Princess Flower dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade, 6-8 hours of direct sunlight daily for best flowering
💧
Water: Keep soil consistently moist but not waterlogged during growing season. Water deeply and regularly, especially during hot weather. Reduce watering in winter. Sensitive to both drought and standing water.
📏
Spacing: 36 inches
📅
Days to maturity: Blooms appear within 1-2 years from young plants; reaches flowering maturity in 2-3 years
🌱
Planting depth: Plant at same depth as container; top of root ball level with soil surface

Soil

Type: Well-draining acidic loamy soil
pH: 5.5-6.5
Amendments:
Peat moss Compost Perlite or sand for drainage Sulfur to lower pH if needed

Growing Zones

Find your zone →

Thrives in zones 9-11; can be grown in zone 8 with winter protection

9a 9b 10a 10b 11a 11b

Sign up free to see if Princess Flower grows in your zone — and get a personalized planting timeline.

Get my Princess Flower timeline →

Growth Stages

1

Establishment

3-6 months

Young plant developing root system and establishing growth pattern with small leaves and stems

Water regularly to keep soil moist. Protect from wind and intense sun. Apply balanced fertilizer monthly. Mulch around base to retain moisture.

2

Vegetative Growth

6-12 months

Plant develops more stems and foliage, becoming bushier with characteristic velvety, lance-shaped leaves

Prune to encourage branching and fuller shape. Continue consistent watering. Feed with acid-forming fertilizer every 4-6 weeks. Maintain humidity if possible.

3

Pre-flowering

4-8 weeks

Plant shows signs of bud formation at branch tips; flower buds appear as small clustered formations

Reduce nitrogen fertilizer slightly; increase phosphorus to promote blooming. Maintain consistent moisture and warmth. Ensure adequate light exposure.

4

Flowering

3-4 months per cycle; can bloom repeatedly through warm season

Showy purple-blue flowers with delicate petals and prominent golden stamens bloom profusely at branch terminals

Deadhead spent flowers to encourage continuous blooming. Maintain consistent watering. Apply low-nitrogen flowering fertilizer every 3-4 weeks. Enjoy multiple bloom flushes.

5

Rest/Winter Dormancy

3-4 months

Plant slows growth, may lose some foliage or appear less vigorous in cooler months

Reduce watering frequency. Withhold fertilizer. Prune to maintain shape and remove dead wood. Protect from frost below 50°F; move containers indoors if needed.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Lime-loving plants Drought-tolerant Mediterranean herbs Plants requiring alkaline soil

Common Pests

  • Increase humidity through misting. Spray with neem oil or insecticidal soap. Rinse foliage with water to dislodge mites.

  • Use yellow sticky traps. Apply neem oil or insecticidal soap every 7-10 days. Encourage natural predators like ladybugs.

  • Prune heavily infested branches. Spray with horticultural oil. Apply insecticidal soap for lighter infestations.

  • Remove with rubbing alcohol on a cotton swab. Spray with neem oil or insecticidal soap weekly until controlled.

  • Improve air circulation. Remove affected foliage. Spray with sulfur dust or fungicidal soap. Avoid overhead watering.

Uses

🍳

Ornamental edible flowers

Culinary

The flowers are technically edible and can be used as a decorative garnish for gourmet dishes, though they are primarily valued for ornamental beauty rather than flavor. [source]

🏠

Cut flowers and arrangements

Household

The showy purple-blue flowers are excellent for fresh floral arrangements and tropical-themed indoor displays, lasting several days in water. [source]

💊

Traditional herbal remedy

Medicinal

In traditional medicine, particularly in Brazil, leaves and flowers have been used to make infusions for various ailments, though scientific evidence is limited. [source]

🦋

Pollinator attraction

Wildlife

The abundant nectar-rich flowers attract bees, butterflies, and hummingbirds, making it an excellent choice for pollinator gardens. [source]

🎨

Landscape specimen plant

Craft

As a striking ornamental shrub, Princess Flower serves as a focal point in tropical and subtropical gardens, adding vibrant color and textural interest to the landscape. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Princess Flower is grown for ornamental flowers rather than harvest. Cut flowering stems for arrangements when blooms are fully open. Remove spent flowers regularly (deadheading) to promote continuous blooming throughout the growing season. Prune after flowering season ends to maintain shape and size.

Fun Facts

  • 🌱 Princess Flower gets its common name from its regal, delicate purple flowers with uniquely arranged stamens that resemble a princess's crown.
  • 🌱 The plant is native to Brazil and is sometimes called 'Glory Bush' in its native habitat, where it grows in tropical highland regions.
  • 🌱 The velvety texture of the leaves comes from fine hairs on the leaf surface, which also helps the plant conserve moisture in humid tropical climates.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Princess Flower planting timeline

Tell us your zip code and we'll calculate exactly when to start Princess Flower seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Princess Flower timeline →