pronounced: koh-dih-EE-um var-ee-GAR-tum
Codiaeum is from the Malaysian word for the plant, codebo; variegatus, in Latin, means ‘having different colours’. The common name, croton, comes from a similar, but different genus of plant, and is from the Greek word κροτων (kroton), a tick, due to the fact that the seeds of the (true) Croton look like those creatures.
Crotons have been popular in tropical gardens for many years. Indeed, many gardens in Townsville used to consist almost entirely of them, grown for the exotic tropical colours of their leaves, and for the fact that they needed virtually no looking after at all once they became established.
Codiaeum variegatum is a native of Ambon Island in Indonesia. The Dutch naturalist Georgius Rumphius in the 17th century introduced the plants to western horticulture. Unlike most plants, they are classified according to the shape of their leaves.
The groups or varieties include: broad leaf, long narrow leaf, oak leaf, and semi-oak leaf. The ‘interrupted leaf’ variety is peculiar in that the centre vein continues to grow beyond the leaf, and another section of leaf forms at its end. There is also a ‘spiral leaf’ variety, that looks rather as if it has come from science fiction. There are literally hundreds of different crotons, and Australia has had a long love affair with them. There are quite a few Australian-bred varieties, such as:
• Africa, popular because of the shape of its foliage and its varied coloration that gives it an overall autumnal look;
• Togo is intensely yellow, with pink stems;
• Zambesi has bitter yellow new foliage that matures into strong pink;
• Mammy is a pretty, dense, bushy plant;
• Zanzibar has long narrow leaves, almost like hairs, usually a fiery red colour if grown in full sun, but a softer colour if grown in the shade.
It may be thought odd to describe this colourful plant as ‘evergreen’, but, technically, it is! The leaves are alternate, anything up to about 20 cm long, leathery, brightly variegated, usually in green, yellow, red, orange or white combinations, and even some purples. Crotons are monoecious. The female flowers are tiny, star-shaped, yellow in axillary racemes, and the male flowers are like fluffy balls.
Old plants tend to become very leggy, but improve with pruning. Pruning will often ‘restore’ the old colours of the plant that may have faded or changed colour with age. Leaves will also lose colour if grown in the shade.
Crotons are now used extensively as pot plants, even in temperate climates. Most of the earlier varieties experienced extensive leaf drop when moved inside, but new varieties have been developed that will handle lower light levels and cooler temperatures, and also keep their leaves.
When a collection of crotons is grown en masse, the mixture of strong colours can be somewhat overwhelming, and today they are generally used more sparingly in association with other plants.
The Croton Caterpillar Achaea janata uses this as a food plant.
When a croton leaf is punctured, it leaks a white sap, that will stain clothes and may irritate the skin – this tends to happen with most members of the family Euphorbiaceae.