French tarragon is a highly valued culinary herb, prized for its distinct, subtle anise-like flavor that is a staple in French cooking. Since it does not produce viable seeds, it must be grown from cuttings or root divisions, making maintenance important for a continuous supply. Regular pruning manages the plant’s growth habit, preventing stems from becoming long and spindly. Consistently trimming promotes dense, lateral branching, keeping the plant full and healthy while concentrating aromatic essential oils in the leaves.
Establishing the Pruning Schedule
The life cycle of tarragon dictates a staggered pruning schedule that spans the entire growing season. The first pruning occurs in early spring, just as the plant emerges from dormancy and new shoots begin to appear. At this time, remove any remaining dead, woody, or damaged stems from the previous year to encourage strong, fresh growth from the base.
From late spring through summer, pruning is synonymous with harvesting, which maintains the herb’s flavor potency. Allowing the tarragon to bolt, or produce flowers, signals the plant to focus energy on reproduction rather than leaf production. This significantly diminishes the concentration of flavorful essential oils. Consistent harvesting suppresses flowering and rejuvenates the plant to produce tender new shoots until mid-fall, or until growth naturally slows.
Technique for Regular Harvesting and Shaping
For routine harvesting and shaping during the main growing season, use sharp, sterilized scissors or hand pruners to make clean cuts. Clean cuts minimize damage and the risk of introducing disease. For maintenance cuts, remove no more than one-third of the plant’s total height at any one time to prevent undue stress on the perennial.
The cut should be made just above a leaf node, which is the small bump on the stem where leaves or a branch junction meet the main stalk. Cutting above this point stimulates the dormant buds within the node to activate and produce two new side shoots. This forces the plant to branch outward instead of growing straight up. Strategically cutting the outer stems slightly shorter than the central ones helps manage the plant’s shape, encouraging a dense, rounded form and preventing flopping. Frequent, light harvests every three to four weeks are more beneficial than one severe trim, ensuring a steady supply of fresh leaves and continuous bushy growth.
Essential Hard Cutback for Winter Dormancy
A hard cutback is required in late fall to prepare the tarragon for winter dormancy. This final cut should be performed after the plant has completely stopped producing new growth, typically following the first light frost when the foliage begins to yellow and die back naturally. Proper timing is important because cutting too early can prompt tender new growth that will be killed by the cold, wasting the plant’s stored energy.
Using clean shears, all remaining stems should be cut back significantly, leaving only a short stubble of about two to four inches above the soil line. This reduction of above-ground material focuses the plant’s remaining resources into the root crown, helping it survive cold temperatures. After the cutback, clear any fallen debris from around the base to reduce the chance of fungal diseases or pests overwintering. In cold climates, applying a light layer of straw or mulch over the crown provides insulation.