Corymbia citriodora
lemon-scented gum
North-eastern Australia (Queensland)
Overview
Corymbia citriodora is an evergreen tree growing 80-115 feet (25-35 m) tall, occasionally to 130 feet (40 m), with a straight, slender trunk and an open crown spreading 30-50 feet (9-15 m). The bark is smooth, powdery, and sheds in thin flakes, ranging from white and pale grey to pink and copper as it ages and renews. Adult leaves are narrow and lance-shaped, 4-8 inches (10-20 cm) long and 0.4-0.8 inch (10-20 mm) wide, mid-green, and release a strong lemon scent when crushed from citronellal in the oil glands. White flowers 0.6-1 inch (15-25 mm) across form in clusters of three at the branch tips, with numerous stamens. Flowering occurs mainly in winter, from June to September in the native range. Woody urn-shaped capsules 0.3-0.5 inch (8-12 mm) long follow and hold the seed for months. The tree grows quickly in warm climates and develops a deep root system that draws on subsoil moisture. It withstands drought and light frost once established, but young trees are damaged below 28 F (-2 C). Surface roots and shed bark create litter beneath the canopy.
Native Range
Native to north-eastern Australia, mainly Queensland, with scattered populations in northern New South Wales. It grows in open forest and woodland on well-drained slopes and ridges.Suggested Uses
Grown as a shade and feature tree in parks, large gardens, and along rural roads in warm climates. It is planted in plantations for citronella oil and durable timber. The flowers are a nectar source for bees and birds.How to Identify
Appearance
Size & Dimensions
Height80' - 115'
Width/Spread30' - 50'
Reaches mature size in approximately 20 years
Bloom Information
Flowering occurs mainly in winter, from June to September in the native range and in the corresponding cool months in Northern Hemisphere cultivation. White flower clusters 0.6-1 inch (15-25 mm) across open over several weeks at the branch tips. Flowering is heavier in some years than others depending on rainfall.
Detailed Descriptions
Foliage Description
Mid-greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow Corymbia citriodora in full sun and well-drained soil with a pH of 5.5-7.5; it tolerates sandy, loamy, and gravelly ground. Once established it draws on deep subsoil moisture and needs irrigation only in extended drought. The tree is sensitive to high phosphorus, so a low-phosphorus fertilizer suits it in spring. It withstands light frost to about 28 F (-2 C), with young trees more vulnerable to cold. The large size and surface roots make it suited to parks and large gardens rather than positions close to buildings and paving.Pruning
Prune in the first few years to establish a single straight leader and clear lower branches. Removing deadwood and crossing limbs in late summer maintains an open crown. Heavy cuts into large limbs can lead to decay and weak watersprout regrowth.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer