French tarragon, which can sometimes be known as Estragon, is the Aston Martin of herbs....needs a little fine-tuning to run but its flavour and impact are second to none. It is quite a large herb with dark green, narrow leaves that are long and smooth. The strong, slightly aniseedy flavour plays many roles in French cooking but is most famously used in Bearnaise sauce. In summer, tiny insignificant yellow flowerheads appear in little sprays, but the seed rarely ripens unless it is super hot. The leaves definitely taste better before it flowers, so it is worth trimming the herb once you see flowers forming. The fantastic flavour of French tarragon begins to diminish after about three years so you will need to take cuttings or just buy some more plants at that point. For many, tarragon is a bit of acquired taste, in which case we have many other herbs for sale that you might like from prosaic parsleys to lemony thymes.
Like many things French, this tarragon can be a little temperamental because it does not like having its roots wet, and it does not like frost. So an obvious solution is to keep it in pots using a bark and grit mix of compost. Make the pot big enough to hold the runners that it will inevitably produce. Water in the day time and sparingly but regularly. Do not feed it because the leaves become too succulent and then tasteless. In winter when the plant is dormant do not water it at all, but keep it somewhere frost-free. If you grow tarragon in the garden, ensure that it is somewhere that does not suffer from winter wet soil otherwise it will die. Like sage and thyme, it requires a sunny site to give of its best. Harvest the leaves in early summer, ideally before the plant has flowered, and pop a sprig or two into a bottle of white wine vinegar to use for sauces and dressings. Chop the fresh herb into anything chickeny, fishy or eggy for a real hit of flavour.
Apart from sounding like one of The Three Musketeers, beware impostors. French Tarragon has a far superior flavour to Russian tarragon but the latter is often passed off as the former. Russian tarragon is taller and coarser...and will survive frosts. Popular in the Tudor court, Henry the Eighth is said to have cited Catherine of Aragon's reckless use of tarragon as one of his reasons for wishing to divorce her.