Codiaeum Variegatum

In the wild. The Australian Plant Census accepts two varieties here: var. moluccanum, native to Queensland, and var. variegatum, which it records in Queensland as naturalised. The CSIRO rainforest key describes the native variety, which it calls garden croton, as a shrub usually 1 to 3 m tall in the understorey of lowland and upland rainforest on Cape York Peninsula and in north-east Queensland, from near sea level to 800 m. By its account the shrub is commonest where the rainforest is driest, and on young basalt soils. HortFlora gives var. variegatum, under which it files the named cultivars it describes, as cultivated through the tropics and not known in the wild.

Position, soil and water. No Australian reference read gives growing conditions, so these come from North Carolina State Extension, an American reference. It gives full sun or part shade, in a well-drained soil rich in humus, and says the leaves colour best in bright light with some direct sun, while too much shade may cost the plant its lower leaves. It waters liberally from spring to autumn and sparingly in winter, and gives the plant a rest with less water from autumn to late winter.

Cold. The same reference rates it for USDA zones 11 and 12, suggests it outdoors where it is protected from frost, and brings plants indoors when the temperature reaches 10 C (50 F). No reference read gives croton a frost rating on an Australian scale.

Pests and propagation. North Carolina State Extension reports that spider mites sometimes limit its use indoors to the short term. HortFlora gives cuttings or seed for the genus.

Croton is grown for its leaves: North Carolina State Extension says the wild type is plain glossy green and the cultivars, of which it counts hundreds, are grown for their variegated foliage. Writing for the United States, it suggests croton, where it is protected from frost, as a foundation plant, a hedge or a specimen, and also in containers and as a houseplant. The Queensland Poisons Information Centre describes it as cultivated for its colourful foliage in tubs or in the garden. No reference read gives planting centres for a croton hedge. Growers' lines under the plain name have pages of their own, Croton and the mixed Assorted Croton, beside the named cultivars.

On a list, croton appears as the plain species and under cultivar names, and the leaf is what tells them apart. HortFlora separates the cultivars it describes by leaf shape, margin and colour alone, from the narrow, purple and red mottled leaf it gives 'Captain Kid' to the wavy, oak-leaf-like burgundy, green, red and yellow leaf of 'Petra'. Quote the same name across growers before comparing prices; the table above shows the sizes growers list. What to look for in the roots, the stem and canopy and for pests is set out in the guide to nursery plant quality. Stock moving between states travels under the state and territory biosecurity rules like any other plant.

The Queensland Poisons Information Centre lists croton as potentially toxic and an irritant to skin or eyes: chewing the leaves, bark or roots causes a burning feeling in the mouth, and contact with the clear sap has caused dermatitis and eczema. For any eye exposure it says to rinse with water for 15 minutes and seek urgent medical help. North Carolina State Extension adds that the sap stains fabric permanently and advises washing the hands thoroughly after handling it.