Silver Beet and Beetroot are staples of the Kiwi diet, but I guess you are talking about beetroot. Beetroot is one of my first harvests from my summer garden, pulling them out, steaming and bottling just a few days before Xmas...if I have a bumper crop I give jars away as presents. A Tomato, beetroot, cucumber and lettuce sandwhich, all from my garden is my summer lunch. I also roast them and use them in cooking, or grated in salads. A hamburger in NZ is not a hamburger unless it has beetroot. Always a can in the cupboard, and a bowl of slices on the table in summer is how it's always been.
Silverbeet grows all year round here....just been out in the garden and counted 12 silverbeet plants, they are weed in our garden.