Ginger can be planted from March through to November in the tropical regions of Australia.
It is grown from rhizomes (which are the part you use in cooking) and will take approximately 6 months from planting until it is ready to harvest. When planting, the rhizomes should be planted directly into their final position (either in a pot or directly in the garden bed) and should be spaced about 15 cm apart.
You can plant the Ginger you buy from the supermarket but it may have been treated with growth inhibitors to increase shelf life. It may have also been treated with various chemical fertilisers and/or pesticides.
You can get “seed” Ginger from nurseries and seed retailers, however make sure you get edible Ginger as there are many ornamental varieties which are not suitable for use in the kitchen.
If any rhizomes are exposed as the plant grows, just cover them up with some soil and they will be fine.
If you decide to go the perennial route, be careful not to damage the plant too much when harvesting.
You can treat Ginger as an annual and pull up the entire plant each year once the plant has fully died back or you can run it as a perennial and just bandicoot some Ginger as and when you need it.