Valerian (Valeriana officinalis), a widely cultivated herb, is prized for the properties found in its root system. These properties are linked to various chemical compounds, including valerenic acids and volatile oils, which accumulate in the underground structures. Properly harvesting and preparing this perennial root is important to maximize its potency and overall yield.
Identifying Valerian and Necessary Tools
Valerian is a perennial plant that can reach up to six feet in height. It features opposite, compound leaves with multiple pairs of toothed leaflets and a noticeable hollow central stem. In midsummer, the plant produces clusters of small, fragrant flowers that are typically white or pale pink.
The most definitive characteristic is the root itself, which carries a unique, musky odor often described as pungent. This distinctive smell, which is highly attractive to cats, is apparent when the root is bruised or crushed. Before harvesting, gather the necessary tools: a sturdy digging fork, a sharp knife or hand pruners for cutting back foliage, and a bucket or wheelbarrow for transport.
Determining the Optimal Harvest Time
Harvest timing directly influences the concentration of active chemical components, such as valerenic acids, within the root. Valerian is primarily harvested in the fall of the second year of growth, just before the plant enters winter dormancy. At this stage, the plant has directed its energy and metabolites into the root system, resulting in the highest concentration of desired compounds.
The plant is ready when the above-ground foliage begins to dry up and die back, often after the first light frost. Harvesting earlier is suboptimal because the roots have not fully matured, leading to a lower concentration of volatile oils. To minimize soil adhesion and ensure efficient digging, cease irrigation for five to seven days before the harvest so the soil is dry or moderately moist.
Technique for Extracting the Root Mass
The process begins by removing the aerial parts of the plant to clear the work area. Using a sharp knife or pruners, cut the hollow stems and foliage down to about two inches above the soil line. Removing the tops first also prevents the seeds from scattering, which helps control the plant’s spread.
To extract the root mass without causing damage, use a digging fork rather than a spade, which can easily sever the fibrous rootlets. Insert the fork approximately 12 to 18 inches away from the central crown to loosen the soil widely around the plant. The valerian root system features a central rhizome with numerous delicate rootlets, so recover as much of the entire mass as possible.
Once the soil is loosened on all sides, carefully use the fork to lever and lift the entire root crown and its associated rhizomes from the ground. Immediately shake off any large, loose clumps of dirt before placing the root mass into a bucket or wheelbarrow for cleaning. Minimize the time the roots spend exposed to air before washing and drying begins.
Cleaning, Drying, and Storage
Immediately after extraction, the roots must be thoroughly cleaned to remove soil and debris. Avoid aggressive scrubbing or scraping, as this can inadvertently remove beneficial components located near the root surface. A gentle method involves placing the roots in a large container of cool water and repeatedly swishing them to dislodge the remaining dirt.
After washing, larger, thicker root crowns must be cut into smaller pieces to ensure thorough and even drying. Cutting the roots into sections no more than half an inch thick significantly reduces drying time and prevents the interior from retaining moisture, which could lead to mold.
The prepared root pieces should be dried in conditions that maintain the integrity of the active compounds. The ideal drying environment involves constant ventilation and temperatures ranging between 95°F and 113°F (35°C to 45°C). Temperatures higher than 105°F can degrade the volatile oils.
The roots are considered dry when they are brittle, hard, and have lost approximately two-thirds of their fresh weight. Once dry, store the valerian root in airtight containers, such as glass jars, and place them in a cool, dark location to minimize the degradation of valerenic acids.