There are a number of species of Abutilon, but the ones seen in our gardens are generally hybrids. They are long-flowering soft-wooded shrubs usually growing to between 1 and 2 m tall, with a similar spread. Known colloquially as Chinese lanterns (which the flowers do resemble), the hybrids are derived mainly from South American species. They prefer a mild to warm climate and are perfectly suited to Sydney gardens, and are quite resilient to our increasingly hot summers.
The colours of the flowers include white, yellow (both pale and vivid), orange, tangerine, red and various shades of pink. Flower shapes can vary from being quite tight to very flared and open. Some have calyces in a contrasting colour, which enhance the flower. There are a number of named cultivars, but few gardeners know the names of the ones in their gardens; they are usually referred to as 'the white one', 'the small orange one' etc. One very pretty small-flowered tawny orange one seems to have the name 'Copper Kettle'. One with green-and-white variegated leaves and a peach flower is called 'Souvenir de Bonn'.
They seem ideally suited to a part-shade spot (as long as they get at least half a day's sun) but do not cope so well with full shade, where they can become straggly. They will also grow in sun, but are so useful for part shade. They bloom over a long period: from early autumn to November in Sydney gardens. Late November seems to be the best time to prune them as they enter a quiescent phase for several months around that time.
They are prone to a nasty leaf-rolling caterpillar in summer which can defoliate a plant in just a few days. Use Dipel, Yates Success or pyrethrum for a low-toxic spray. I have found Yates Success to give pretty good results; it is based on a bacteria rather than a harmful chemical. You may need to apply these treatments a couple of times to achieve control. They can also be attacked by flea beetles, which can make many holes in the leaves. Neem oil may help to control them. Try a drench of neem oil around the plant at the end of winter to control the larvae. Abutilon can get very woody after a while, and may need to be replaced with a fresh plant struck from a cutting. Older plants seem more vulnerable to pests. Cuttings taken in autumn or spring will take root easily if kept in a humid environment. Abutilons can be trained as standards: begin when the plant is young and has a single stem. I've seen some examples where a couple of different coloured versions and plaited together to give a rather impressive result.