Valerian

Growing Conditions

Growing Zones

Thrives in USDA Zones 3 - 9

Companion Planting

When to Plant

• Start Indoors

  8 to 10 weeks before last frost

• Transplant

  After last frost, once soil has warmed to at least 50°F

• Direct Sow

  Direct sow in early spring as soon as soil is workable, or in autumn for spring germination

• Harvest

  Harvest roots in autumn of the second year when foliage begins to die back; harvest flowers in early summer when clusters are just opening

Organic Growing Tips

• Top-dress around the root zone each spring with finished compost or worm castings to fuel the large, deep root system valerian develops in its second and third years.

• Apply a thick layer of straw or leaf-mold mulch in late autumn to protect the crown in zones 3 to 5 and to conserve the soil moisture valerian roots require.

• Water with compost tea monthly during the growing season to maintain the soil microbial community that supports deep-rooted perennials.

• Valerian is a dynamic accumulator; chop-and-drop spent foliage around companion plants in autumn to return minerals including phosphorus to the soil surface.

• Allow a few plants to self-seed at the edges of the bed each year to maintain a rolling succession of first- and second-year plants without starting from scratch.

• Avoid high-nitrogen organic amendments such as fresh manure in the root zone late in the season, as they push leafy growth at the expense of root development heading into dormancy.

Common Pests

• Aphids
• Slugs
• Spider mites
• Powdery mildew

Taxonomy

Kingdom

Plantae

Family

Honeysuckle family (Caprifoliaceae)

Genus

Valeriana

Species

officinalis

Natural History

Valeriana officinalis is native to Europe and temperate Asia, growing naturally along stream banks, damp meadows, and woodland edges from Britain east to Japan. The genus name derives from the Latin valere, meaning to be strong or well, and the plant was documented in Greek and Roman medical writing, including by Dioscorides in De Materia Medica in the first century CE. Medieval European herbalists called it All-Heal and cultivated it widely in physic gardens. Ecologically, valerian's deep taproot mines minerals from subsoil layers, making it a valued dynamic accumulator in permaculture polycultures, while its midsummer flowers are a magnet for hoverflies and native bees.

Traditional Use

Valerian root has one of the longest documented histories of any European medicinal plant, appearing in Greek, Roman, medieval, and early modern herbalism primarily in association with sleep and nervous conditions. The root was listed in official pharmacopoeias of Britain, Germany, and the United States well into the twentieth century. Its distinctive earthy-fetid odor when dried comes from isovaleric acid released as the fresh root compounds break down.

• Dioscorides, De Materia Medica, first century CE - root

  Dioscorides recorded the root under the name Phu, noting it as warming and diuretic and describing its use in Greek and Roman medical contexts as a provocation of urine and menstruation.

• Medieval European physic garden tradition, 9th to 15th centuries - root

  Benedictine monks and later apothecaries cultivated valerian root in physic gardens across Europe; it appeared in the Capitulare de Villis of Charlemagne (circa 812 CE) as a plant to be maintained on imperial estates, and was widely documented in monastery herbals as a calming agent.

• British Pharmacopoeia and German Commission E, 19th to 20th centuries - root

  Valerian root was an official entry in the British Pharmacopoeia from 1864 onward and was extensively reviewed by Germany's Commission E in the late twentieth century, representing an unusually well-documented transition from folk herb to official pharmacopoeial listing.

Valerian root is generally regarded as safe for most adults in ordinary garden and culinary-herb contexts, but the fresh root and foliage are mildly toxic to some animals, and cats may become agitated or intoxicated by the root compounds. Long-term concentrated root extract use and interactions with sedative medications have been noted in clinical literature.

This information is provided for historical and educational purposes only and is not medical advice. Always consult a qualified healthcare professional before making decisions related to your health.

Morphology (Plant Structure & Identification)

• Root System

  Valerian develops a dense, fibrous root crown with a thick central taproot that becomes significantly larger and more aromatic in the second and third years; division of this crown in spring or autumn is the most reliable propagation method for established plants.

• Stem

  Hollow, ribbed stems rise 3 to 5 feet tall in the second year, branching near the top into a corymb of flower clusters; cut spent stalks to the ground after bloom to redirect energy into root development.

• Leaves

  Pinnately compound, dark green leaves with 7 to 10 pairs of lance-shaped leaflets; lower leaves are large and coarse, while upper stem leaves are smaller and paired; yellowing or wilting in midsummer is usually a moisture stress signal rather than disease.

• Flowers

  Dense, flat-topped clusters of tiny pale pink to white flowers open in June and July and are intensely fragrant, attracting hoverflies, bees, and butterflies; allow some to go to seed for self-sowing, but deadhead remaining clusters to prevent weedy spread.

• Fruit

  Each tiny flower produces a single achene tipped with a feathery pappus that aids wind dispersal; seeds are short-lived and should be collected and sown fresh for best viability.

Known Varieties

Common cultivars worth knowing

• Valeriana officinalis (Common Valerian)

  The standard species grown for medicinal root production; reaches 4 to 5 feet with pale pink flowers and the most well-documented root chemistry among all valerian forms.

  Best for: Root harvest and medicinal garden use

• Valeriana officinalis 'Compacta'

  A shorter, more compact selection reaching 2 to 3 feet, better suited to smaller gardens or mixed borders without the aggressive spreading of the species.

  Best for: Smaller gardens and ornamental mixed borders

• Valeriana phu 'Aurea'

  A closely related ornamental species with striking golden-yellow spring foliage that fades to lime-green by summer; grown primarily for its foliage effect rather than medicinal root quality.

  Best for: Ornamental foliage and spring color in the border

• Valeriana wallichii (Indian Valerian)

  A Himalayan species used in Ayurvedic tradition, with smaller stature than V. officinalis and a distinct root chemistry; sometimes grown as an ornamental or specialty medicinal herb in warmer zones.

  Best for: Warmer climates, zones 6 to 9, and specialty medicinal growers