The Gymea Lily (D. excelsa) originating from a region around Sydney provides a spectacular flower display on a stem 3-6 metres high. You need to be pretty tall or have a high vantage point to get the most out of this flower. The Spear Lily (D. palmeri) native to northern NSW and south east Queensland also produces its flower on a large stem though this bends over providing a stunning flower at ground level.

Both have sword like leaves up to 3m long and large red flowers on very large red terminal heads (about 500mm across). Sweet nectar is produced over a period of several months attracting many nectar feeding birds to your garden.
Doryanthes plants prefer to be grown in full sun or part shade and will rot if the soil is boggy. While its foliage is frost tolerant, the developing flower needs to be protected.

As the plant grows larger, its stem draws deeper into the soil giving it the ability to withstand extended dry periods. It does however require deep friable soil to perform this task. The growth of a Doryanthes plant will be restricted in heavy clay soil. I know of a 10 year old plant in these conditions which is less than 1m high.

The Doryanthes will present well as a pot specimen for a number of years and is a good alternative to the more delicate Agave attenuata. Be aware that the plant will not be restricted by its confined quarters, preferring to break out of the pot as its stem swells. If planting in your favourite ceramic pot, be sure to pot up or plant out early enough to avoid the problem.
From seed, the Doryanthes will take 8-10 years to flower. So the gardener who cannot wait that long should obtain an advanced plant. Otherwise, be patient and enjoy the foliage until the flowers eventually arrive.