It sounds almost like the title of a spy novel, doesn’t it? Well, there is in fact more than a bit of international intrigue involved when you’re shopping for tarragon for your garden. You’ll need to draw on your investigative skills to make sure you buy the right plant.
There are, in fact, two tarragons on the market: French tarragon (Artemisia dracunculus sativa) and Russian tarragon (A. dracunculus dracunculoides, sometimes simply written A. dracunculoides). The two were derived from the same wild plant, but are definitely not equivalent, especially when it comes to cooking.
French tarragon is the aromatic herb made famous by French cuisine. It is one of the four official “fines herbes” recommended by French chef Auguste Escoffier in the early 20th century for use in egg, fish, and chicken dishes, the other three being parsley (Petroselinum crispum), chives (Allium schoenoprasum) and chervil (Anthriscus cerfefolium), a quartet still promoted by chefs of the French persuasion worldwide.
It’s believed that French tarragon was actually selected in Italy some 600 years ago, an extra-flavorful mutation found among wild tarragon, then was spread throughout Europe by monks. It was first mostly used as a medicinal herb before finding a more permanent place as a culinary plant.
French tarragon has a distinctive taste: a very intense mixture of anise and camphor with its own special touch. It’s strong enough that you only need a pinch when cooking. Its lanceolate leaves are medium green and borne on a shrubby-looking plant about 24 to 30 inches (60 to 80 cm) high.
French tarragon rarely blooms and when it does, the flowers are often deformed and any seeds it produces (and there won’t be many) are sterile or nearly sterile. If ever you do get a seed to germinate, the plant won’t have the proper French tarragon taste; it will have reverted to the flavor of wild estragon
That’s why you have to propagate French tarragon vegetatively, by stem cuttings, layering or division.
Over all, it’s a fairly short-lived plant: even under ideal conditions, you need to take cuttings every few years to keep it going. It does best where the winters are mild, yet summers aren’t hot, about hardiness zones 5 to 7, although it may survive in zone 4 if protected. Most people don’t even bother putting efforts into overwintering it: if it’s not alive come spring, they simply buy a new plant.
Russian tarragon is an impostor. It has little taste and is not considered of much use in cooking. It forms a larger plant (up to 5 feet/1.5 m tall) and its foliage is paler green than its cousin’s. It produces an abundance of fertile flowers and sometimes self-sows excessively, just as it may become invasive due to its rhizomes, although quite honestly, it expands quite slowly. It is much hardier than the French tarragon (zone 3, occasionally even zone 2) and will easily survive the winter in most colder climates.
Even though Russian tarragon has little culinary value, it is commonly offered on the market. You’ll find seed packets of tarragon, for example, but they necessarily contain seeds of Russian tarragon, since French tarragon doesn’t produce viable seed. Nursery shelves are sometimes filled with pots of Russian tarragon, because they can grow it inexpensively from seed, which makes it much more profitable than cutting-grown French tarragon.
Curiously, Richters Herbs, one of the world’s largest supplier of herbs, sells both kinds, but begins its description of Russian tarragon with “Not recommended”. One hopes buyers take notice of the warning!
… And the Ugly
Honestly, all tarragons are fairly ugly, or at least, definitely on the less attractive side of the Artemisia genus, which otherwise gives us so many silvery-leaved, ornamental perennials and subshrubs: silver mound (A. schmidtiana), white sage (A. ludoviciana), etc.
How to Buy the Right Tarragon
You can get true French tarragon from all sorts of mail order sources, such as the aforementioned Richters Herbs. And garden centers do carry it. You have to hope the plants are correctly labeled, though, as the two are pretty similar in their youth, although French tarragon is a darker green compared to the pale green of Russian tarragon (you have to see them side by side to really notice the difference). Of course, if the label only says “tarragon”, you’re probably looking at Russian tarragon.
Personally, if in doubt, I wait until nobody is watching, then pull off two or three small leaves and munch on them. If the taste is intense, in fact, out and out bitter, it’s French tarragon. If they have little to no taste, it’s Russian tarragon.
Grow both types of tarragon the same way, in full sun in very well drained—even dry—soil. The substrate doesn’t even need to be very rich (too much nitrogen weakens the leaves’ taste). And be forewarned: Russian tarragon can become invasive.
Now that you’ve discovered tarragon’s dirty little secret, you’ll be able to confidently choose a tarragon plant for your own herb garden.