Lemon Eucalyptus

A young lemon-scented gum grows fast, often shooting up as a slim, unbranched pole in its first years. With age it forms a tall trunk topped by an open, rounded crown that casts only light shade. The smooth bark sheds each year in thin, curling flakes. As the old layer drops away, it reveals fresh bark beneath in shades of white, pink, and pale copper. This yearly renewal keeps the trunk looking clean and polished. Young trees carry broad, dull green leaves. As the tree matures, the leaves narrow into the long, curved, glossy blades that hang from the branches of older specimens.

In its native woodlands of northeastern Australia, this tree grows on shallow, sandy soils over sandstone. These lean, fast-draining soils shaped its tough, drought-adapted roots. Like many eucalypts, it forms a lignotuber – a woody swelling at the base of the trunk that stores buds and energy. This swelling lets the tree resprout after fire or damage. Once established, it handles heat, dry spells, and full sun with ease. It does need room, since it grows tall and fast, and its wood can be brittle. Cold is its main limit. Hard frost burns the foliage, and a deep freeze can kill even large trees. The summer flowers offer nectar that feeds honeybees and other insects.

The lemon scent of the crushed leaves comes from oils rich in citronellal, a natural compound with a sharp, citrus smell. People distill these oils into oil of lemon eucalyptus, which is widely used as an insect repellent and in perfumes. The same tree is grown in plantations across Australia, Brazil, Africa, and Asia for its oil and hard timber. In the garden, it works well as a shade tree or a tall specimen where space allows. A few cautions are worth noting. The leaves and concentrated oil can upset the stomach if eaten, and the oil may irritate skin. The tree also sheds bark and drops leaves and limbs, and its foliage is flammable, so give it room away from structures.