Tarragon is a highly sought-after culinary herb, prized for its subtle, anise-like flavor that elevates many dishes. Whether this herb is a perennial depends entirely on the specific variety you are growing and your local climate. Understanding the differences between these types is fundamental for any gardener seeking a continuous supply.
Defining the Types of Tarragon
The most popular variety, French tarragon (Artemisia dracunculus var. sativa), is a true, hardy perennial. It is the preferred culinary type, offering a distinct, sweet licorice flavor essential to French cuisine. Hardy in USDA zones 4 through 8, it rarely produces viable seeds and must be propagated asexually.
Russian tarragon (Artemisia dracunculoides) is also a perennial and is significantly hardier than the French variety, surviving down to USDA Zone 3. However, its flavor is noticeably milder and less refined. It readily produces seeds, making it easy to grow but less favored by chefs.
Mexican tarragon, or Mexican mint marigold (Tagetes lucida), belongs to a different genus. It serves as an excellent substitute, particularly in hot, humid climates where French tarragon struggles. This variety is perennial only in warmer regions (USDA Zones 8 through 11) and is grown as an annual elsewhere.
Essential Overwintering Care
Successful overwintering, especially for French tarragon, requires preparation in the fall. Once the first hard frost kills the above-ground foliage, cut the stems back to a few inches above the soil line. This signals the plant to enter dormancy and directs energy to the root system for winter survival.
Applying a thick layer of protective mulch insulates the shallow root crowns from temperature extremes. Spread a 2-to-4-inch layer of organic material, such as straw or shredded leaves, over the base once the ground begins to freeze. This prevents damaging freeze-thaw cycles that can heave the roots out of the soil.
Gardeners in colder zones may opt to grow French tarragon in containers to provide protection. Potted plants should be moved to a sheltered, unheated location, such as a cool cellar or garage, for the winter. During dormancy, drastically reduce watering to keep the soil barely moist. This prevents root rot caused by cold, soggy conditions.
Propagation Methods for Maintaining Stock
Since French tarragon does not reliably produce viable seed, gardeners must rely on vegetative propagation. The most common method is dividing the established root clump every few years to renew the plant’s vigor. This process is best performed in early spring as new growth emerges or in the fall after the foliage has died back.
When dividing the plant, a clean, sharp knife should be used to separate the brittle root mass into smaller sections, ensuring each piece has several healthy buds or shoots. Another reliable technique for French tarragon is taking softwood stem cuttings from new growth during the spring and summer. These cuttings are typically 4 to 6 inches long and are dipped in a rooting hormone before being placed in a sterile, well-draining medium to develop new roots.
In contrast, Russian tarragon can be easily propagated by all three methods: seed, division, or cuttings, due to its vigorous and less sterile nature. The flexibility in propagation for Russian tarragon makes it a simpler plant to establish and expand in the garden than the more flavorful French variety. Mexican tarragon can also be grown from seed or propagated by dividing its roots in the spring.