All the good folk from www.warmearth.com.au have recommended that it’s not (see below for good advice from the Warm Earth crowd) too late to plant your garlic so if you don’t have yours in yet then maybe it’s time to get crackng.
There's an old garden tradition that garlic is planted on the shortest day of the year and harvested on the longest, but in actual fact it can go in any time between May and the end of July. Buy seed garlic from your local garden centre or purchase organic, locally-grown garlic bulbs from a farmers' market or greengrocers. Pull the bulbs apart and only plant the fattest outer cloves, as these produce the fattest bulbs. Don't peel off the papery skins. Just poke them in the soil, pointy end facing up, about 5cm deep. Mark the rows so you don't accidentally dig the cloves up again before they've sprouted. Give garlic its own bed and make sure it's weed-free. Mulch after planting and ignore until spring, when you need to regularly water to ensure the bulbs fatten up fast.
All the best and cheers