HARDY GARDENING WITH CULINARY HERBS

Herbs are various kinds of herbaceous plants whose fresh or dried parts are used to season foods, provide fragrances, supply natural dyes or make industrial and pharmaceutical products. Culinary herbs are those whose fresh or dried leaves are used in cooking; some common culinary herbs are basil, French tarragon, rosemary and thyme.

Culinary herbs are usually distinguished from spices, although the two categories overlap. Culinary herbs generally consist of fresh or dried leaves, while spices are seeds, roots, fruits, flowers and bark. Culinary herbs usually have a mild flavor, while spices tend to have a stronger, pungent flavor. Several common spices are cinnamon sticks, anise seeds and ginger roots. This fact sheet discusses primarily the common culinary herbs for home gardens and landscapes.

Herb Selection:

The beginning herb gardener might want to start by growing herbs such as basil, chive, dill, oregano, parsley, sage and thyme. These herbs can be grouped in "classic" herb gardens, and can be incorporated into flower beds or vegetable gardens.

Planting:

Most herbs will grow well with the same sunlight, fertility, soil, growing conditions, and cultural techniques required by vegetables grown in hardy gardens. Gardeners should pay special attention to drainage and moisture requirements of certain herbs, since many are very sensitive to soil moisture conditions. Sage, rosemary and thyme require a well-drained, slightly moist soil, whereas parsley, chervil and mint grow best on soils which retain moisture. Raised beds may provide the necessary moisture and drainage requirements for herbs that require good soil drainage.

Basil:

Basil, French basil or sweet basil (Ocimum basilicum) is a popular, tender, annual herb. Basil is native to India and Asia and is grown for its aromatic leaves, which are used fresh or dried as a flavoring. Basil can be direct-seeded or transplanted to the garden in late spring, after all danger of frost is past. The seeds normally germinate in 8-14 days. Basil requires full sun and prefers moist and well-drained soil with a pH of 6.0. Typical spacing for basil is 12 inches between plants and 24 to 36 inches between rows.

Basil grown for dried leaves or essential oil is cut just prior to the appearance of flowers. The foliage should be cut at least four to six leaves above the ground to allow for regrowth and a subsequent crop. Japanese beetle, Fusarium and powdery mildew are potential insect and pest problems on basil plants.

Chives:

Chives, Allium schoenoprasum, are perennials native to the Orient. Fresh leaves are excellent for making herbal vinegars and butter and the blooms can also be used in herbal vinegars. Chives are often used in salads, soups and cheeses. For successful germination, chive seeds require darkness, constant moisture and a temperature of 60 to 70 degrees F for best results. Sow seeds 1/2 inch deep in pots or flats; germination will occur in 2-3 weeks. Transplant seedlings to the garden when they are 4 weeks old. Chives reach a height of 18 inches and a width of 1-2 inches the first year from seed; they will spread to 10-14 inches in subsequent years. Chives require full sun and well-drained soil with a soil pH of 6.0. Chives have beautiful purple blossoms and will reseed prolifically if allowed to go to seed. To harvest chives, cut leaves 2 inches above the ground. Although no serious pest or disease problems are common, both downy mildew and rust can infect chives.

Dill:

Dill, Anethum graveolens, is native to the Mediterranean area and southern Russia. Dill is a hardy annual, sometimes grown as a biennial. Dill is commonly used as a seasoning for soups, fish, and pickles. Butterfly larvae feed on dill, making it an ideal plant in butterfly gardens. Dill should be direct-seeded in spring; allow 10 inches for each plant. Since dill has long tap roots, it should not be transplanted. Fresh leaves should be harvested before flowering begins. Harvest seeds as soon as seed heads are brown and dry. Dill does not have any serious pest or disease problems, although phoma blight, rusty root and stem rot have been reported.

French Tarragon:

French tarragon, Artemisia dracunculus, originates from southern Europe (Russian tarragon, Artemisia dracunculoides, is much coarser, has paler leaves, and a more bitter taste). French tarragon is a woody perennial that will grow 2 feet tall. It produces few seeds, and must be propagated by stem cuttings or division. Plant in full sun in rich, well-drained soil with a pH of 6.9. Divide the plants every three to four years. Harvest six to eight weeks after planting and until leaves turn yellow in the fall. French tarragon is prone to root rot in heavy and wet soils.

Mints:

Mints, Mentha spp., are a group of herbs that are mostly native to Europe and Asia. Some are indigenous to South America, America and Australia. European and Asian mints are naturalized throughout North America from southern Canada to Mexico. With the possible exception of Corsican mint, mints are such rampant growers that they will quickly overwhelm other plants. Invasive mints should be planted in sunken clay pots to inhibit spreading.

Japanese mint (M. arvensis var. Piperescens), peppermint (M. xpipita) and spearmint (M. spicata) are the most commonly cultivated species of mint. All mints can be propagated by cuttings or seeds. Peppermint does not produce viable seeds and can only be propagated by cuttings. Mints can be planted in full sun or partial shade and require rich, well-drained soil with a soil pH of 6.5. Mint can be harvested almost as soon as it comes up in the spring. Young, tender leaves and stems are the best. Mint is susceptible to verticillium wilt, mint rust and mint anthracnose. Spider mites, loopers, mint flea beetles, mint root borers, cutworms, root weevils and aphids are all potential pest problems on mint plants.

Oregano:

Oregano, Origanum vulgare subsp. hirtum (also referred to as O. heracleoticum and O. hirtum), is native to the Mediterranean region of Europe and central Asia. It is naturalized in the eastern United States. Oregano is a perennial and can be propagated by seeds. Direct-seed in the garden and do not cover seeds--they need sunlight to germinate. Flavor can vary greatly among seed propagated plants--propagate by root divisions or cuttings from plants that are known to have strong flavor. Oregano reaches a height of 12-24 inches and a width of 10-20 inches. It requires a site with full sun and well-drained soil with a pH of 6.8. Sprigs of oregano can be cut off when the plant is at least 6 inches high. In June, vigorously grown plants can be cut back to the lowest set of leaves. Plants will generally leaf out after two weeks and can be cut back again in August. Potential pest and disease problems for oregano include aphids, leafminers, spider mites and root rot.

Rosemary:

Rosemary, Rosmarinus officinalis, is a tender perennial, hardy to zones 8 to 10. It is native to the Mediterranean region, Portugal and northeastern Spain. Rosemary can be started from seeds, but germination rates are very low. Use fresh seeds, preferably less than two weeks old. Packaged seeds are difficult to germinate. Start plants from cuttings or by layering from existing plants. Rosemary grows slowly from seeds, and eventually reaches a height of 72 inches and a width of 36-72 inches. Plant rosemary in a sunny location with well-drained, slightly acidic soil. Rosemary can be harvested year-round. Cut 4-inch pieces from the tips of the branches, never removing more than 20% of the growth at one time. Pest and disease problems of rosemary include aphids, spider mites, scale, mealybugs, root rot and botrytis.

Thyme:

Thyme, Thymus vulgaris, is native to the western Mediterranean region. It is a small, many-branched perennial shrub. Start seeds indoors and transplant seedlings to the garden once all danger of the frost is past. Thyme reaches a height of 12 inches and a width of 10-12 inches. Thyme can be propagated from cuttings, by layering and division. Harvest the entire plant by cutting it back to 2 inches above ground in midsummer and again at the end of the season. Pest and disease problems include spider mites and root rot.