Artemesia dracunculus is a member of the Asteraceae (sunflower) family.

An aromatic, perennial herb native to Europe, southern Russia and western Asia. The plant reaches a height of 2.5 to 4 feet and is characterized by thin, erect stems, delicate, narrow green leaves, and greenish white flowers.

Use. Tarragon is widely cultivated for its anise flavored leaves used for seasoning. It is also the source of an aromatic, pungent essential oil, called estragon, which can be distilled from the plant and used as a flavoring extract in pickles and tarragon vinegar. The leaves, fresh or dried, are used as seasoning in soups, mayonnaise, butter, stews, sauces, and vinegars. Its flavor is pungent, almost liquorice-like. It is best when used fresh. It is used with vinegar in pickles and to flavor oil. Tarragon is also used in perfumes, soaps, and cosmetics.

Climatic requirements. Tarragon grows best in warm, sunny locations on dry soils with good drainage. The plant is intolerant of standing water or poorly drained soils. According to Simon, Chadwick and Craker the reported life zone is 45 to 63° F (7 to 17° C) with an annual precipitation of one to four feet (0.3 to 1.3 meters) and a soil pH of 4.9 to 7.8.

Propagation and care. Tarragon is best started from seedlings, divisions, or cuttings. Take divisions in the early spring as the new growth appears. Take cuttings in autumn or late spring. Roots spread laterally rather than vertically, so plants must be cultivated carefully, and mulch must be provided over the winter for frost protection. Plants should be divided every three or four years to reinvigorate growth and flavor. The plants can be multiplied by dividing the crown clumps into separate parts. These subdivisions can be set as individual plants. Space root divisions 18 inches apart in rows 3 feet apart. The large crown that develops from the division should be subdivided after 3 or 4 years.

Tarragon plants rarely produce viable seed. Seeds that are for sale may be of the less-versatile False or Russian tarragon (Artemisia dracunculoides), a more vigorous grower that lacks the aromatic oils of French tarragon (A. dracunculus var. sativa).

Harvesting can begin six to eight weeks after setting out. In summer, harvest leaves just as the flower buds appear and continue from time to time until late autumn before the leaves begin to turn yellow. Handle leaves gently, as they bruise easily. When leaves begin to yellow, harvest the whole top, cutting back to about three inches above the ground. Hang the stalks in bunches in a warm, dry place out of direct light. It can be dried, but some color and flavor may be lost. The herb can be chopped fine, mixed with water and frozen in ice cube trays. It can also be frozen in butter.

Postharvest Handling (section by Marita Cantwell). Increased use of fresh herbs for culinary and other purposes has also increased the demand for high quality. The successful marketing of high quality fresh culinary herbs requires extreme care and attention to postharvest handling conditions.

All the postharvest principles that apply to leafy green tissues apply to the handling of fresh herbs. Temperature is the single most important factor in maintaining quality after harvest. Despite the diverse botanical origin of the fresh herbs, the optimum postharvest temperature for fresh thyme, oregano, rosemary, mints, sage, parsley, cilantro, savory, marjoram, dill, and tarragon is 32 F (0 C). Under controlled conditions, a shelf life of 3 to 4 weeks can be achieved at this temperature. With a temperature of 41 F (5 C), a minimum shelf life of 2 to 3 weeks can be expected. If herbs are harvested early in the morning, the need for cooling is minimized. If harvested later, the appropriate cooling method depends on the type of herb. Most respond favorable to room and forced air cooling. Herbs have also been successfully vacuum-cooled. A simple forced air pre-cooler can be constructed for small operations that requires only an adequate coolroom, a fan, and some simple carpentry.

After temperature, prevention of excess moisture loss is the second most important postharvest factor affecting the quality and shelf life of herbs. Most herbs respond favorable with very high humidity (>95%). Some herbs can be held successfully in water (basil, mints, tarragon), whereas water loss in most can best be controlled by packaging and maintaining high humidity in the environment. Lowering the holding temperature to the recommended levels also greatly reduces water loss.

Herbs can be packaged in bags designed to minimize water loss. When herbs are packaged this way, it is particularly important to maintain constant temperatures, to reduce condensation inside the bag and the consequent risk of fungal or bacterial growth. The bags may be partially ventilated with perforations, or may be constructed of a polymer that is partially permeable to water vapor.

The relative humidly in the packing area, cold rooms, and transport vehicles should be maintained at a high level (>95%) where practical.

Ethylene gas is another factor which limits the shelf life of leafy tissues. Ethylene causes yellowing of leaves, and an increased rate of deterioration. It is possible to routinely find one to three ppm ethylene in the environment surrounding fruits and vegetables during commercial handling. Young growing herb tissue responds to ethylene (5 ppm), whereas little effect was observed in mature herb cuttings. In addition, holding the herbs at the recommended temperatures also greatly reduces their ability to respond to ethylene in the environment.

Careful handling to avoid physical injury to the leafy tissue of the fresh herbs is also important. Rigid clear plastic containers such as those sometimes used for sprouts may be used for soft herbs. "Pillow packs" (plastic bags which are partially inflated when sealed) may be an alternative packaging technique. Careless handling results in tissue discoloration, as well as increasing sites for pathogen attack. Growth of microorganisms can also be reduced by proper temperature management and good hygienic practices in the field and packing station. Chlorinated water can reduce microbial load if water is used during handling.

Plant Sources - French:

W. Atlee Burpee & Co., 300 Park Avenue, Warminster, PA 18974.

Park Seed Co., Cokesbury Road, Greenwood, SC 29647-0001.

Gurney's Seed & Nursery Co., Yankton, SD 57079.

Henry Field's Seed & Nursery Co., Shenandoah, IA 51602.

Le Jardin du Gourmet, PO Box 75, St. Johnsbury Center, VT 05863.

Nichols Garden Nursery, 1190 North Pacific Hwy., Albany, OR 97321.

Park Seed Co., Cokesbury Road, Greenwood, SC 29647-0001.

Otto Richter & Sons Ltd., Box 26, Goodwood, Ontario, Canada L0C 1A0.

Stillridge Herb Farm, 10370 route 99, Woodstock, MD 21163.

Taylor's Herb Gardens, Inc., 1535 Lone Oak Road, Vista, CA 92084.

Thompson & Morgan, PO Box 1308, Jackson, NJ 08527.

J.L. Hudson, Seedsman, PO Box 1058, Redwood City, CA 94064.

Pinetree Garden Seeds, Route 100, New Gloucester, ME 04260.

Otto Richter & Sons Ltd., Box 26, Goodwood, Ontario, Canada L0C 1A0.

Stokes Seeds Inc., Box 548, Buffalo, NY 14240.

Vermont Bean Seed Co., Garden Lane, Fair Haven, VT 05743.

Plant Sources - Mexican:

Redwood City Seed Co., PO Box 361, Redwood City, CA 94064.

Otto Richter & Sons Ltd., Box 26, Goodwood, Ontario, Canada L0C 1A0.

Williams, Louis. Drug and Condiment Plants.. Agriculture Handbook 172, USDA. 1960. 37 pp.

Cantwell, M. and M. Reid. Postharvest handling of fresh culinary herbs. Perishables Handling No. 60: 2-4. Vegetable Crops Dept., UC Davis. 1986.

Joyce, Daryl, Michael Reid and Philip Katz. Postharvest handling of fresh culinary herbs. Perishables Handling No. 58:1-4. Vegetable Crops Dept., UC Davis. Feb. 1986

The authors are Yvonne Savio, Vegetable Crops Extension, UCD, Curt Robinson, University Extension, UCD, and Claudia Myers, Small Farm Center, UCD.

Captions:

Figure 1. The Tarragon plant reaches 2.5 to 4 feet high and has greenish white flowers and narrow green leaves. (Photo by Charlotte Glenn).

Figure 2. Tarragon being grown commercially. (Photo by Hunter Johnson).

Reviewed by Jeanine Davis, 12/4/91

Reviewed by Tim Hartz, 1/7/92

1/10/92