Whether growing outdoors or in, herbs adapt well to containers. Be aware that different herbs have different moisture requirements. If you are planning to plant multiple types of herb in a single container, make sure their moisture needs are compatible with one another first. This will make adequate care much easier. Pay attention to light needs as well. Most herbs prefer full sun, though a few do well in partial shade. This will affect where you place the containers once you've planted the herbs. Temperature needs are fairly consistent; no herbs like frost.
Divide herb seeds according to moisture needs. Plant herbs requiring similar amounts of moisture together. Parsley, basil, cilantro and tarragon all prefer soil with a lot of moisture. Most other herbs do not require nearly as much moisture. With the exception of tarragon, you may notice that most annuals need lots of water, while most perennials do not.
Mix potting soil and compost together in a 1-to-1 ratio, and fill your containers. If placing containers indoors, choose windows that get adequate sunlight. If such windows are not available, consider investing in ultraviolet grow lights to aid in healthy herb container gardening.
Sow seeds according to package instructions. Most herb seeds should be planted at a depth between 1/4 and 1/2 inch. Always overseed slightly to account for seeds that will not germinate. You will thin the seedlings out later on in the cycle.
Cover over the newly planted seeds, and lightly pat the soil into place. Mist gently with a mister bottle. This allows you to water the seeds without disturbing them or the soil in which they are planted.
Install a moisture meter in each pot. Since containers dry out much more quickly than in-ground gardens, a moisture meter is extremely helpful in gauging when your herbs need watering. Generally speaking, they should be watered less often, but more deeply. This encourages roots to grow deep and strong, rather than forcing them to grow wide and shallow in order to get scant amounts of water given daily.
Thin herb seedlings according to package instructions when they have reached 3 inches in height. You can transplant the thinned herbs elsewhere, or use immediately in salads, cookery or drink recipes.
Fertilize with a good all-purpose fertilizer according to package instructions. According to Charlotte Kidd of In The Garden Design, a common misconception about herbs is that they thrive in poor soil. When growing in containers, she cautions that it is absolutely necessary to ensure that they are adequately fertilized. Avoid overfertilization, however. Plant discoloration and white, salty formations on the top of the soil and around the edges of the container are indicative of overfertilization. Overfertilizing can burn and damage tender herb roots.