Tarragon

Description

Tarragon, Artemisia dracunculus, is an herbaceous perennial in the family Asteraceae grown for its leaves which are used a culinary herb. The tarragon plant is erect with slender, often branching stems and simple needle-like leaves which are glossy green and very aromatic. The plant produces a drooping head at the end of the stem which contains up to 40 yellow-green florets. Tarragon can reach a height of 1.5 m (5 ft) and can live for many years, dying back in the Winter and regrowing in Spring. Tarragon may be referred to by their cultivar group and these include French tarragon and Russian Tarragon. The origin of the plant is unknown but it has a wide distribution which covers Europe, parts of Asia and North America.



Uses

Tarragon leaves are used either fresh or dried as a culinary herb. Essential oil can be extracted from the leaves and flowers.


Propagation


Basic requirements
Tarragon grows best in temperate climates and can survive some light frost. Tarragon will perform optimally when planted in a dry location in full sun. Soil should be light in texture and well-draining, with a pH between 6.3 and 7.5. Plants tend to perform better in slightly acidic soils. Tarragon will not tolerate wet soil and requires only 300 to 1300 mm of rainfall annually.

Propagation
Tarragon is usually vegetatively propagated from stem or rhizome cuttings. Stem cuttings should be 15 cm (6 in) in length and taken from the shoot tip. Use of a rooting hormone will aid tarragon rooting. Root cuttings should be 5 cm (2 in) in length and should be taken together with a new shoot. Beds should be prepared for planting by incorporating organic matter and an all purpose fertilizer, if desired, into the soil. This should be worked into the top 15–20 cm (8–10 in) of the soil to provide nutrients and improve soil aeration. Tarrago should be planted in Spring after all danger of frost and newly rooted plants should be planted 25 cm (10 in) apart allowing 25–40 cm (10–16 in) between rows.

General care and maintenance
In commercial tarragon production, it is common to mulch fresh plantings with straw to conserve moisture in the soil, suppress weeds and lower the soil temperature. Tarragon roots are tender and this helps them to establish in the soil. Tarragon should be watered regularly bu soil should be allowed to dry out between irrigations. Plants do not require the addition of any fertilizer as the flavor is improved by growing in nutrient poor soil. Tarragon should be pruned regularly to promote branching.

Harvesting
In the home garden, sprigs of tarragon can be harvested as required by pinching 1/3 of the length of the stem. Commercially produced tarragon is first harvested about 2 months after transplanting when the plants are well established. Plants are harvested 2–3 times over the growing season by cutting the tender tops.



References

CABI Crop Protection Compendium. (2008). Artemisia dracunculus (tarragon) datasheet. Available at: http://www.cabi.org/cpc/datasheet/7089. [Accessed 17 April 15]. Paid subscription required.

Herb Society of America (2003). Tarragon. An Herb Society of America Fact Sheet. Available at: http://www.herbsociety.org/factsheets.... [Accessed 17 April 15]. Free to access.

Hudson, B. & Drost, D. (2009). French tarragon in the garden. Utah State University Cooperative Extension. Available at: https://extension.usu.edu/files/publi.... [Accessed 17 April 15]. Free to access.



Common Pests and Diseases

Tarragon rust
Puccinia dracunculina

Symptoms
Yellow or white spots on underside of leaves; bright orange or yellow pustules on underside of leaves; leaves may turn yellow; growth is stunted and plant may become stunted
Cause
Fungus
Comments
Spread of disease favored by poor air circulation around plants; spres are transmitted by wind
Management
Remove all crop debris andd infected leaves; avoid the use of oveerheadd irrigation or water in the morrning to allow plant foliage to dry durring the day; ensure plants are well spaced to promote good air circulatioon around plants