I find the Purple Sicily Cauliflower is incredibly disease resistant. The only problem is that the colour does not hold and often ends up in the cooking water. They do need full sun and moderate watering. Although I find in winter the rains are sufficient to allow it to grow. They love to be mulched. I use my standard mulch cover of whatever I have available which is usually fallen leaves and spent chook hay. I set them out approximately 50 centimeters apart to allow for adequate space between plants to spread their leaves. Every now and then (when I can be bother or when I have it available) I water them with some worm tea.
Harvest your cauliflower when the head is still firm. My favourite way to eat cauliflower at the moment is to make a cauliflower puree, although I am yet to do this with the purple cauliflower as I believe the colour would be an interesting one and may not be pleasing to the eye (I am thinking greyish sludge). What is your favourite way to eat cauliflower?