Garlic cloves were planted in fall, a couple of weeks before our first freezing temperatures. The soil has a lot of organic matter.
Plant 4-6 inches (10-15 cm) apart from each other, with the top of the clove 2 inches (5 cm) below the surface.
Larger garlic cloves will result in larger garlic heads, so plant the largest ones first.
Cover with straw/mulch, then have fun watching Juncos (birds) pick through it all for bugs over the next few months.
I've had to protect them from deer and rabbits chewing them down. Laying tomato cages sideways over them took care of that matter. Later, I added an automatic light, which has worked well in the past.