Fresh herbs can be used to add flavor and variety in the kitchen, or dried and used to make teas. Many herbs are also used for medicinal and aromatic purposes. Although most herbs prefer warm, arid climates, herb plants thrive in the temperate, marine climate of the Pacific Northwest with a bit of planning. Plant herbs in the spring, after you're sure any danger of frost has passed.
Decide what herbs you want to grow. You may want to try your hand at culinary herbs such as tarragon, parsley, thyme or sage. Aromatic herbs such as basil, rosemary or mint can be used both in the kitchen and in aromatherapy treatments or perfumes. Herbs like lavender, borage and valerian are often planted for their ornamental value, in addition to their culinary or medicinal traits.
Visit a nursery or garden center that specializes in herbs. Choose healthy, garden-ready herb plants. Avoid plants that have yellow or brown leaves, and plants that look unhealthy, or long and leggy. You may also choose to plant herb seeds, but plants are usually a better choice in the Pacific Northwest's cool, damp springs.
Choose the warmest, sunniest spot in your garden, since most herbs need at least six hours of sunlight per day. Avoid spots exposed to cold winds, or those that are prone to early-morning frost. Most importantly, choose a spot where the soil drains well. No herb will tolerate damp, soggy soil. If rainwater puddles for more than four hours, choose another spot or amend the soil.
Prepare the spot. Cultivate the soil to a depth of at least 10 inches. Add 3 to 5 inches of compost or well-rotted manure, and work it into the soil. If the soil doesn't drain well, amend the soil by adding an extra 3 to 4 inches of peat moss, or plant your herbs in a raised bed constructed of railroad ties, bricks, cement blocks or lumber.
Dig a hole for each herb plant. The hole should be just large enough to accommodate the plant's rootball. Plants buried too deeply can easily rot.
Water the herb plants immediately after planting. Keep the soil damp for the first three to four weeks, then water only when the top of the soil feels dry to the touch. Most herbs do well in dry soil. Always water early in the day so excess moisture will have time to evaporate before evening.
Be sure the herbs have ample air circulation, which will help prevent disease and fungus, which are common in the Northwest's damp climate. Allow several inches between plants. Pull weeds as they appear, and rake up fallen leaves, grass clippings and other debris that can harbor disease and pests. Remove any wilted leaves or dying plants.
Harvest herbs when the buds are just beginning to open. Harvesting herbs on a dry, sunny day will ensure the highest concentration of flavor and aroma. Wait until late morning, after the dew has evaporated.