We think of herbs as plants that provide pungent accents in cooking, but technically, all non-woody plants that flower and reproduce by seed are herbs. We use a fraction of the "kitchen" herbs grown by our ancestors, but a wide variety is available each spring at garden centers. Grow herbs in a garden or flower border for their beauty and fragrance; preserve them to bring good taste to the table all year long.
According to West Virginia University's Extension, one English nursery boasts "57 herbs, 16 mints, 17 onion-type herbs, 20 sages, and 17 thymes in a recent catalog." Nearly dozen types of mint alone crowd some nursery racks. The gardener who tries to plant them all will need a garden the size of the ones that graced 18th century estates. The practical gardener chooses garden herbs that will be used in the kitchen and adds some that have attractive flowers or foliage to brighten the plot.
Most herbs require slightly acidic, well-drained soil in a sunny location, although some like tarragon and catnip do better in semi-shade. West Virginia's horticulturists suggest digging out gardens with heavy clay to a depth of 18 inches and refilling with sandy loam over a 3-inch layer of crushed stone to improve drainage. Most herbs grow best when soil is not fertilized; nitrogen produces larger leaves but less intense essential oils. Give herbs a winter mulch of straw or evergreen boughs in December. Leave mulch in place until the air warms in spring; herbs start growing early and can use the shelter.
The oils that give herbs their flavor are most intense when the plant is actively growing. Pinching back pants delays flowering and provides fresh herbs for kitchen use. Keep a bunch of mint stems for tea or basil for pasta at hand in a glass of water in the fridge. The North Carolina State University Extension recommends beginning harvest when plants have enough foliage to support growth and continuing to harvest until flower buds form. Harvest herbs in the morning when they are actively growing and hydrated.
Traditional Preservation Techniques
Gardeners and cooks have used two methods of drying to preserve herbs for centuries. Because oils are released when leaves are crushed, both methods emphasize keeping leaves whole. One method hangs loosely tied small bunches in well-ventilated, dark spaces; this method works best with low-moisture or fine-textured herbs like thyme, sage, dill and parsley. The second method, best used with large, moist herb leaves like those of basil, bay and mints, dries them quickly by spreading individual leaves on screening. Herbs will retain their strength for several months to a year.
North Carolina State's Extension suggests several additional ways to preserve garden herbs. Freeze chopped herbs in ice cubes or freeze whole herbs spread on trays; store both in the freezer in plastic bags. Microwave herbs spread on paper towels on high for a few minutes--thick leaves will need another "zap." Spread herbs on trays in food dehydrators or in an oven on the lowest setting. Herbs are finished when leaves crumble. Keep leaves as whole as possible while removing from stems and store in freezer bags or sealed jars. Check packages periodically and discard any that show signs of mold, a sign of incomplete processing.