Garden soil needs to be loose and well drained, with a pH of 6.5-7.0. If your soil is heavy or loaded with clay, you will need to loosen it with compost, peat moss or other organic matter. Remember, most herbs are grown for eating. For Midwesterners, turning over your garden in the fall and working in leaves, grass, manure, compost or peat moss gives the organic matter time to break down over the winter months. Right after the frost is out of the garden in the spring is another good time to add organic matter.
Herbs hate wet feet.
It causes root rot and a host of other problems for your plants and can eventually kill them. Always try to water your gardens early in the morning. This way the plants have moisture to carry them through the day. If it is a particularly hot day, you may need to water again between five and six p.m. Soaker and perforated hoses are particularly effective in herb gardens. Regular fertilizing of your herb garden is not something you really need to be concerned with unless you are breaking new ground and you need to amend the soil.