Propagation
Sow fresh seeds in flats at a depth of 14 mm (⅝ in) and cover with a layer of sand to 7 mm (¼ in) thick and maintain a temperature of 16º to 18º C. (61º to 64º F). 

Prick out and pot up when they are large enough to handle. Germination may take up to 12 months and the seedlings are very slow to grow.

Note:
It is commonly confused with Xanthorrhoea media but this plant is normally found in wetter soil types. This plant re-shoots after fire.

Botanic information
Leaf: The thickish linear leaves are up to 3 mm (1/8in) wide and quadrangular in cross section. The texture is leathery and stiff and the leaves are arranged in a radiating rosette.

Flower: The tiny white star-shaped flowers are arranged densely on the upright ridged spike. The spike has a velvety appearance from the dark hairs on the floral bracts and the flowering period may vary depending on bush fires, but generally they appear from late winter to summer. 

Fruit: The fruit is a leathery 3-valved loculicidal capsule that contains flat dull black seeds that have endosperm. The seeds are viable but the plant is commonly transplanted as a mature specimen.

General information on Grass Trees.
These very slow growing plants are only found in Australia and live to 600 years.  It takes up to 10 years for the trunk to appear and is composed of masses of old leaf bases that are held together with natural resin. 

Then it takes a further 20 years for a crown of thin linear leaves to form distinctly above the trunk which has a growth rate of 20 mm (¾in) per year. Some species can attain a height of over 4 m (12ft) and are commonly branched.  
The flowering stem appears every two to three years on mature plants and grows rapidly up to 30 mm (1⅛in) per day and the inflorescence attracts honey eating birds, bees, butterflies and ants.