Robin Gale-Baker, from Sustainable Macleod, discusses the tarragons. This is one of a series of articles she has written about growing various herbs (see right hand sidebar). She has also written a number of articles about growing various veggies, growing various fruit trees and general growing techniques. If you want to read more about the various herbs, she recommends The Encyclopedia of Herbs and Herbalism, edited by Malcolm Stuart and originally published in 1979.
There are three tarragons, each bearing an international name but not necessarily the name of the country of their origin. Like those countries – France, Mexico and Russia – they are very different from each other and, unless you can distinguish one from another, your cooking may lack that distinct anise flavour you are after. French and Russian tarragon are readily confused as they look similar (although the former has darker and glossier leaves). Mexican tarragon, on the other hand, has its own distinct appearance and beautiful gold yellow flowers.
French tarragon (Artemesia dracunculus) comes from Russia (Siberia) and is considered the best of the tarragons. It is a highly prized herb in French cuisine, having a deep anise/liquorice taste. It is particularly well known in roasted tarragon chicken recipes where it is chopped and mixed with softened butter and massaged into the chicken beneath the skin. It is also used with fish, eggs and in vinegars, dressings and sauces, including Bearnaise and beurre blanc sauces. It is an ingredient of ‘fines herbes’ along with parsley, chervil and chives.
Russian tarragon (Artemesia dracunculoides) is a much inferior herb with little, if any, anise/liquorice taste. It tastes more like grass and I can’t think of any reason to grow or use it.
Mexican tarragon (Tagetes lucida), also known as winter tarragon, is a member of the Asteraceae family like the other two but is from a different genus – the marigold genus, Tagetes. However, it has great similarity in taste to French tarragon and the advantage that it flourishes over winter rather than dying down. It produces heads of bright, yellow marigold-like flowers which, if dead-headed when they wither, will continuously produce flowers throughout the winter. Planting Mexican tarragon plus French tarragon will ensure that you have a year round supply of this delicious herb.
All tarragons require a warm, sunny position, well drained soil, neutral to slightly acidic on the pH scale and prefer to be watered once a week and then left to dry out. Over-watering will diminish the essential oils and therefore the taste. Tarragons do not like wet feet and may die in wet conditions. In climates colder than Melbourne, the roots may require the protection of mulch in winter. When planting, incorporate some compost mainly to aerate the soil.
French tarragon can only be propagated vegetatively – that is by root division or cuttings in spring. It rarely flowers and, if it does, does not produce viable seed. It is an herbaceous perennial and, as such, will die down late autumn/early winter but will shoot again early spring. When it dies down, it is best to prune it back to ground level, and every 3 years dig it up, divide its coiled roots and re-plant so that the roots do not strangle it. Russian tarragon can be propagated from seed, division or cuttings, as can Mexican tarragon. All 3 varieties are hardy and none suffer from pest attack.