Chu-lan tree (Aglaia odorata)

Overview

The Chu-lan tree, formally known as Aglaia odorata, is prized globally for the intense, sweet lemony fragrance emitted by its tiny yellow flowers. This broadleaf evergreen hails from the dense forests of Southeastern Asia and brings an element of exotic perfume to any garden or sunroom it inhabits. While it grows as a small tree or large shrub in its native range, cultivation often keeps it managed at 8 to 10 feet tall.

Distinctive features of the Aglaia odorata include glossy, pinnate compound leaves and sprays of miniscule, ball-shaped flowers that bloom intermittently throughout the year. The fragrance is particularly notable during the daytime, making it a treasured choice for warm-climate landscaping or as a substantial container specimen. Gardeners in marginal zones rely on its container adaptability to protect this specimen from cold snaps.

This plant offers significant ornamental value beyond its scent. Whether used as a hedge, a striking specimen, or a beautiful houseplant indoors, the Aglaia odorata provides year-round green structure contrasted by those coveted, highly fragrant yellow blooms. Success with the Chu-lan tree hinges on providing consistent moisture and protection from freezing temperatures.

Fast Facts

• Plant Family: Meliaceae
• Plant Type: Broadleaf evergreen
• Native Range: Southeastern Asia
• Hardiness Zones: USDA Zones 10-11
• Size at Maturity:
  • Height: 8-10 ft
  • Spread: 8-10 ft
• Bloom Time: Seasonal bloomer
• Bloom Description: Yellow
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

Planting the Chu-lan tree should be done where it is fully hardy, specifically USDA Zones 10 or 11. In these areas, Aglaia odorata thrives in medium-moisture, moderately fertile, well-drained soils. While it tolerates full sun, gardeners in hot summer climates should locate the plant where it receives some afternoon shade to prevent scorching.

For care, maintain medium water needs, ensuring the soil is consistently moist but never soggy; avoid wet soils at all costs. In container settings, water moderately, allowing the top part of the soil to dry slightly between waterings, but prevent the root ball from drying out completely. This plant appreciates normal room temperatures indoors, with a minimum winter temperature of 60°F recommended for optimal health.

Container culture is essential for zones outside of its tropical range. Utilize clay pots, which offer better breathability. Move containers outside in late spring once frost danger has passed, but ensure they are brought back indoors before temperatures approach 40°F in the early fall. Propagation is typically achieved via cuttings or air layering, as viable seed production is often rare, especially on female plants.

Landscape Uses

Where winter hardy, the Aglaia odorata integrates beautifully into the landscape as a defining specimen shrub or small tree due to its evergreen nature and intoxicating fragrance. It can be formally pruned into dense hedges or allowed a more natural, rounded form near entryways where the daytime floral scent can be fully appreciated. The small stature, topping out around 10 feet, makes it manageable for urban gardens or courtyards.

For non-hardy locations, the Chu-lan tree excels as a sophisticated potted plant. It serves as an excellent, aromatic focal point on patios during the warmer months. Once indoors for winter, its glossy foliage and subtle flower sprays provide excellent texture in sunlit rooms, functioning as a beautiful houseplant near south-facing windows.

The fragrant flowers of the Aglaia odorata have historical and cultural uses; in places like Hawaii, they are used for making leis and worn ornamentally in the hair. Consider planting near seating areas or windows where the morning and afternoon perfume of the flowers can be easily detected.

Standout Features

Flower Qualities

• Showy
• Fragrant

Noteworthy Characteristics

Aglaia odorata, frequently called the Chinese perfume tree, is a glabrous evergreen recognized in the mahogany family. In cultivation, it maintains a manageable size of 8 to 10 feet, though it can reach 20 feet in the wild across regions like China, Taiwan, and Vietnam. It displays yellow-green foliage and sprays of tiny yellow flowers that appear like miniature balls, emitting a powerful, sweet lemony scent primarily during the day. The genus name honors Aglaia, one of the Greek Graces, referencing the plant’s beautiful aroma.

Potential Problems

No serious insect or disease problems are typically noted for the Chu-lan tree. The primary concern for indoor or container growers is watching for sporadic infestations of mealybugs. Employ regular inspection, especially on the undersides of leaves, and treat isolated spots promptly with horticultural oil or insecticidal soap to maintain the health of your Aglaia odorata.

Tolerances

Frequently Asked Questions

What hardiness zones is Chu-lan tree suitable for?

The Chu-lan tree is winter hardy only in USDA Zones 10 through 11. Gardeners outside this range must grow it in containers that can be moved indoors before night temperatures approach 40 degrees F.

How large does Aglaia odorata grow?

This evergreen typically reaches a height and spread between 8 to 10 feet in cultivation, though it can grow significantly taller in its native habitat if left unpruned.

When does Aglaia odorata bloom?

The plant is a seasonal bloomer, and blooms appear intermittently throughout the year, displaying sprays of tiny yellow flowers that are intensely fragrant during daylight hours.

What sun exposure does Chu-lan tree need?

Aglaia odorata performs best in full sun to partial shade conditions. In very hot summer environments, providing some light afternoon shade for the foliage is beneficial.

Conclusion

The Aglaia odorata, or Chu-lan tree, is an indispensable plant for warm-climate landscapes and discerning container gardeners due to its unparalleled, sweet, daytime fragrance and attractive evergreen structure. Its moderate maintenance requirements make it a rewarding choice for adding subtle luxury to a patio or sunny room. Before planting, always confirm your local USDA hardiness zone compatibility or prepare to treat it as a protected houseplant.

Propagation Tips

Since fruiting is rare, traditional propagation of the Aglaia odorata relies on vegetative methods. Cuttings taken from semi-hardwood stem tips are the most common approach for home growers seeking to replicate a known fragrant female plant. Ensure cuttings are placed under mist or in a high-humidity environment to encourage root development, as success rates are often better when humidity is carefully controlled.

Air layering presents another reliable, though slower, method for obtaining established specimens of the Chu-lan tree. This technique involves girdling a branch, applying rooting hormone, and wrapping the area in moist sphagnum moss covered securely with plastic. Once roots have formed, the new plant can be severed from the parent, yielding a robust plant ready for its own container.

Container Growing

Growing the Chu-lan tree in pots is the standard practice for most gardeners outside its native tropical environment. Clay pots are specifically recommended as they allow the soil to breathe, which is crucial given the plant’s intolerance for wet soil conditions. Proper drainage must be ensured, as blocked drains or heavy, water-retentive soil quickly lead to root issues.

When managing Aglaia odorata indoors, place the container near the brightest available window, usually south-facing. Water moderately, focusing on consistency; the key is allowing the soil surface to dry between waterings but never permitting the entire root ball to become bone dry. This bright, partially shaded, consistently moist but well-drained scenario replicates the preferred sheltered, bright forest floor habitat of the plant.