A=Annual B=biennial P=Perennial TP=Tender perennial

Anise-(A)- The green leaves can be cut off whenever the plants are large enough. The seeds are ready when they turn brown. Wash In warm water, drain thoroughly, and allow to air dry.
Use: The leaves can be used in salads, soups, beverages, meats, game, and poultry. The seeds are used to flavor cakes, bread, and cookies. Leaves and seeds also add a delightful scent to sachets and pot-pourris.

Basil, Sweet-(A)- For fresh use, harvest the leaves as they mature-about 2 weeks after planting. For dry use, harvest leaves just before the plant blooms.
Use: One of the most popular herbs, used mainly with tomato and egg dishes, stews, soups, and salads, but also with many vegetable, poultry, and meat dishes.

Caraway-(B)- The seeds are harvested after they turn a gray-brown color. Scald the seeds in boiling water, then dry thoroughly.
Uses: Use the seeds in breads, cakes, cookies, potato salad, and baked fruit (apples, for example). Also can be used in Hungarian-type dishes, coleslaw, sauerkraut, cheese spread, meat stews, and fish casseroles.

Chervil-(A)- For fresh use, pick the tips of stems once a month. For dry use, harvest leaves just before the blossoms open. Dry on trays.
Uses: Use fresh leaves the same as you would parsley, such as in salads, salad dressings, soups, egg dishes, and cheese souffles.

Chives-(P)- Leaves can be harvested any time during the growing season. Cut them off close to the ground. Can be pureed with water in a blender and frozen in ice cube trays.
Uses: Chives add a mild onion-like flavour to dips, spreads, soups, salads, omelets, casseroles, and many kinds of vegetables

Coriander-(A)- The leaves, which are only used fresh, can be cut for seasoning as soon as the plants are 4 to 6 inches tall. The seeds can be harvested when the heads turn brown.
Uses: Coriander seeds smell and last much like a mixture of sage and orange and can be used in baking, poultry dressings, and French salad dressing. Much used in Chinese, Middle Eastern, and Latin American cuisine.

Dill-(A)- The fresh leaves can be harvested as needed and used as seasoning. Seed heads should be harvested then the seeds ripen to a light brown color.
Uses: Leaves and seedheads are most commonly used in the making of dill pickles. The leaves also add a characteristic flavour to salads, cottage cheese, soups, fish dishes, omelets, sauces, and vegetable casseroles. Dill seeds are sometimes used in pasteries, sauces, sauerkraut dishes, and for flavoring vinegar.

Fennel-(TP)- The leaves can be harvested and used fresh. Fennel seeds are harvested when the seed heads turn brown. Dry in a paper bag. Florence fennel is harvested when the bulbs are large enough.
Uses: The anise-flavoured leaves and seeds of this herb are widely used in fish dishes, cheese spreads, and vegetable dishes. The leaves and stems can be used in much the same way as celery. Florence fennel bulbs are used in salads or as the main ingredient in a salad.

Lavender-(P)- The whole flower spikes are cut just before the florets are fully open and when color and fragrance are at their best.
Uses: Lavender is most often used in sachets, perfumes, and potpourris.

Lovage-(P)- Harvest young, tender leaves and use fresh. You can dry or freeze the leaves for later use.
Uses: Use the celery-flavoured herb in soups, stews, potato salads, meat and vegetable dishes. It can also be eaten raw like celery. Its seeds are sometimes used in salads, candies, breads and cakes.

Majoram, Sweet-(A)- Cut back to 1 inch above the ground just before flowering; a second crop will form for later use. Easily dried or frozen.
Uses: Use Marjoram leaves with meat, poultry, vegetable dishes (especially green beans), potato salad, and egg dishes.

Mints-(P)- Harvest before flowering and use fresh or dried. Cut off near ground level. A second cutting can be harvested later on.
Uses: Used primarily for flavouring. The leaves are often put into teas and other beverages, as well as lamb sauces and jellies.

Oregano-(P)- Harvest and dry before flowering occurs.
Uses: Oregano imparts a sharper flavour than Sweet Marjoram. It is used to season spaghetti sauces and tomato dishes. Its flowers are attractive in summer arrangements.

Parsley-(B)- Snip young leaves just above ground level, as needed.
Uses: Use as a garnish in soups, salads, meats, and poultry.

Rosemary-(TP)- Harvest the young, tender stems and leaves, but avoid taking off more than one-third of the plant at one time. For drying, harvest just before the plant flowers.
Uses: A gourmet seasoning for meats, poultry dishes, and potatoes. Use either fresh or dried.

Sage-(P)- Harvest when just starting to flower and use either fresh or dried.
Uses: A commonly used seasoning for meats, stuffings soups, and salads.

Summer,Savory-(A)- You can gather young stem tips early, but when the plant begins to flower, harvest the entire plant and dry.
Uses: Used to flavor fresh garden beans, vinegars, soups, stuffings, and rice.

Tarragon,French-(P)- Harvest tarragon in June for steeping in vinegar. For drying, harvest in early to mid-July.
Uses: Often used in various sauces such as tartar and white sauce, and for making herb vinegar.

Thyme-(P)- Put leafy stem ends and flowers when plants are at the full-flowering stage. Use fresh, hang-dry, or freeze.
Uses: Used in combination with other herbs. Leaves can be used with meats, soups, sauces, and egg dishes.

SOURCE:
"Harvesting and Drying Herbs" by James C Schmidt and Dianne Noland Department of Horticulture, University of Illinois at Urbana-Champagne, Cooperative Extension Service, College of Agriculture HM-1