If you have clay or heavy, compacted soil, do not add peat moss to increase drainage. Add sand instead. Peat moss will lower the pH and make the soil more acidic. Sand will not affect the pH of the soil. If your soil is very poorly drained, you should consider raised beds for your herb garden.
Most herbs respond poorly to overfeeding.
Fertilize in early spring with organic fertilizers such as well rotted manures, compost, fish emulsion, and cottonseed meal. There are three types of herbs, perennials, biennials, and annuals. Perennial herbs, once established, will live for several years. In northern areas, some perennials such as rosemary and bay, must be protected in winter or treated as annuals. In addition to rosemary and bay, other perennials include mint, thyme, chives, oregano, sage, and tarragon.