Growing garlic is fun & easy and it is one of the most useful things to grow in the garden - not only because its great to eat and keep colds away and helps to make you healthy, but because the flowers are wonderful through the garden and its great for companion planting for lots of plants.
It was always the 'rule of thumb' I thought that you planted garlic and most of the onion family at the winter soltice, or shortest day of the year for harvesting after the longest day of the year. This apparently is sort of right but I haven't got it quite right and its a bit more complicated than that..... you can plant garlic now and still harvest successfully, but its also good to get it in earlier during Autumn.
Sometimes it depends on the variety but from all the reading I have done it really doesn't matter for our cool climate. I imagine that planting it in Autumn would mean better and fatter bulbing by the time you harvest.
So...if you are like me and have missed the autumn planting then get some in now. I just buy bulbs from the shop and put them in. Separate the bulblets, plant at about 5 cm deep and try to make sure they are right side up. Don't plant any that are squishy, moulded or not healthy.
They dont' like to be too wet as the bulbs will rot and disappear. Mound the soil if you need to. I plant mine all through the garden and let half it go all the way to flowering as it is lovely to have huge allium flowers in the garden.