Katsura (Cercidiphyllum japonicum) is a tree that is native to China and Japan1. This pretty tree is a potentially pleasing addition to an ornamental garden setting because of its attractive foliage, and most notably because of its delicious caramel scent in autumn.
What Does it Look Like?
Katsura is a medium-sized tree which grows to a height of about 40 feet in 20 years. It has attractive heart-shaped leaves. In spring, the leaves emerge with a bronze tint, then turn pale green in summer. In autumn, the leaves change colour again, becoming a buttery yellow if they are grown in soil with neutral to alkaline pH, or turning orange or pink in more acidic soil. The tree is deciduous, so it loses its leaves in winter.
The trees are either male or female and produce small flowers in spring - the male tree's flowers have red stamens and the female flowers have red styles. If a male tree is flowering nearby for pollination, the female tree's flowers will develop into thin 1cm-long fruits in late summer, each containing several seeds.
What Does it Smell Like?
In autumn, from the time when they change colour until the time when they fall off for the winter, the Katsura leaves release their scent2. Variously described as like candy floss/cotton candy or burnt sugar, the scent gives the Katsura its nickname of the caramel tree.
What can Gardeners do with it?
Katsura is a good garden tree that has an Award of Garden Merit3 from the Royal Horticultural Society. It grows best in a sheltered spot protected from frost. It is happy in the sun or in more shady areas. The tree requires well-drained but moist soil, so may need watering during hot dry spells of weather. It is not particularly vulnerable to any pests or diseases and doesn't require pruning4.
The tree is particularly suitable planted near a bench or other seating so that its autumnal scents can be enjoyed to the full by people sitting and relaxing in the shade of its branches.