The most spectacular flower in Australia is the Gymea Lily, also known as the Giant Lily, and to botanical folk as Doryanthes Excelsa. They produce a once per year display during April and May. There are several Gymea Lilies slowly opening in the Sydney Botanic Gardens. You still have time to fly out here to see the lilies in full bloom.
Of the Gymea Lilies in my front garden, only one is flowering this year because they are still young. They take up to ten years to start flowering. Each year they grow bigger and produce a new flower bigger than the year before.
Small Gymea Lilies are the diameter of a small pizza. After many years of growth, they can produce a flower head the diameter of a large pizza. Hold your arms out in a circle. Imagine your arms filled with just one flower head.
I include shots of a local plant that opened early because it is well watered and in full afternoon sun. This plant shows what the other plants will show toward the end of May.
Doryanthes Excelsa is also called the Flame lily because of the colour. Their size gives them the name Giant lily. They look a bit like a spear from a distance and are also called the Giant spear lily. The Dory part of Doryanthes is Greek for spear. Anthos is Greek for flower and contributes the second part of Doryanthes.
Plants in many areas of Australia are adapted to bush fires in summer and and autumn then rain across winter and spring. Doryanthes Excelsa expects fire then rain. A mature plant can flower after fire, the seeds will fall on fresh clear soil, and the rain will help them grow. Some commercial flower growers use fire to stimulate flowering.
You could try the simulated bushfire at home but you are most likely to kill the plant and burn down your house. In Sydney in winter the leaf cover on your garden can be dry underneath and carry a smouldering fire to your fence or house. Fires around plants in the wild occur frequently and keep the fuel cover, all those dead leaves and branches, light. We put out bushfires in the wild then the fuel builds up to the point where the next fire kills the plant. In our gardens, we pile up mulch and that produces a long lasting fire of intense heat that kills the plant.If you do experiment with fire, rake all the mulch away and use only a light layer of dry grass or a couple of newspaper pages.
Ethylene is a gas that ripens fruit and stimulates some plants into flowering, including Doryanthes Excelsa. Some people place a stone in the centre of the plant to stimulate ethylene production but the stone can damage the growth point. The stone probably works by blocking the sun and has the same effect as falling leaves or ash from a bushfire.