Thanks Snadger and Mrs D!
At the moment I've got parsley, oregano, lemon balm, rosemary, thyme and sage, and I will be planting some borage, coriander, chives and marjoram. Some of the spokes will have two herbs, and if it gets too crowded I can always move them. Mint and basil will go in pots on the path. What have you gone for Snadger?