How to Grow Valerian for Herbal Use: When to Plant, Best Varieties & Care Guide

Intro for growing valerian for herbal use

Valerian (Valeriana officinalis) is a perennial flowering herb prized for its medicinal root, which has been used for centuries as a natural sedative and sleep aid. This tall, elegant plant with its sweet-scented white or pink flowers not only serves as a valuable herbal remedy but also adds architectural interest to garden borders. Growing 1.5-2 meters (4-6 feet) tall, valerian thrives in moist, well-drained soil and adapts to various temperate climates. Whether you’re looking to harvest its roots for homemade tinctures and teas or simply enjoy its attractive umbels of flowers, valerian is a rewarding addition to any medicinal herb garden and relatively straightforward to grow.

When to plant valerian for herbal use

Valerian is best planted in spring after the last frost has passed or in early autumn in temperate regions. The soil temperature should ideally be between 15-21°C (60-70°F) for optimal germination. In cooler northern regions (UK, US Zones 4-5), spring planting is preferable to give plants time to establish before winter. Valerian is frost-hardy once established and can withstand temperatures down to -20°C (-4°F), making it suitable for most temperate gardens. In Mediterranean or warmer climates (US Zones 8-9), autumn planting allows roots to develop during the mild winter months.

Best time to plant valerian for herbal use

For cool temperate regions (UK, Northern Europe, US Zones 4-6), plant valerian from mid-April to early June when soil has warmed. For warmer regions (US Zones 7-9), September to October is ideal for planting. Direct sowing works well in spring, but starting seeds indoors 6-8 weeks before the last frost date gives plants a head start. Transplant seedlings outdoors when they reach 10-15 cm (4-6 inches) tall. In Mediterranean climates, October to November planting allows roots to establish during winter rains before summer heat arrives.

Best valerian varieties to grow

• Valeriana officinalis – The classic medicinal variety with the strongest sedative properties in its roots.
• Valeriana sitchensis (Pacific Valerian) – Native to North America with similar properties to common valerian but better adapted to western regions.
• Valeriana jatamansi (Indian Valerian) – Suited to warmer climates and valued in Ayurvedic medicine.
• Centranthus ruber (Red Valerian) – More ornamental with striking red flowers, though less medicinal value.
• ‘Aurea’ – Decorative variety with golden foliage that brightens herb gardens while maintaining medicinal properties.
• ‘Alba’ – Features pure white flowers that stand out beautifully in evening gardens.
• ‘Anthos’ – Compact variety (60-90 cm/2-3 ft) suitable for smaller gardens and containers.

How to plant valerian for herbal use

Materials needed:

• Valerian seeds or seedlings
• Compost or well-rotted manure
• Garden fork or tiller
• Watering can or hose with spray attachment
• Mulch (straw, leaf mold, or compost)
• pH testing kit (optional)

Step-by-step planting:

1. Select a site with partial to full sun and moist, well-drained soil with a pH between 5.5 and 7.0.
2. Prepare the soil by digging in 5-7 cm (2-3 inches) of compost to improve drainage and fertility.
3. For direct sowing, scatter seeds thinly on the soil surface, as valerian seeds need light to germinate.
4. Gently press seeds into soil without covering them completely.
5. For seedlings, dig holes 30-45 cm (12-18 inches) apart, as valerian grows quite large.
6. Plant seedlings at the same depth they were in their containers.
7. Water thoroughly after planting to settle the soil around roots or seeds.
8. Apply a 5 cm (2-inch) layer of mulch around plants, keeping it away from stems to prevent rot.
9. For container planting, choose pots at least 30 cm (12 inches) deep to accommodate the long roots.

How to grow valerian for herbal use

Valerian prefers partial shade to full sun, with afternoon shade beneficial in hotter regions. Water regularly to maintain consistently moist soil, providing about 2.5 cm (1 inch) of water weekly, more during dry spells. Fertilize sparingly—too much nitrogen promotes leaf growth at the expense of root development. Apply a balanced organic fertilizer (like 5-5-5) once in spring when growth begins. Mulch with compost or straw to retain moisture and suppress weeds. Valerian rarely needs pruning, but removing flower heads before they set seed prevents unwanted self-seeding. For container growing, use pots at least 40 cm (16 inches) deep with drainage holes, and water more frequently as containers dry out faster than garden soil. In hot climates, move containers to shadier spots during summer heat.

Caring for valerian for herbal use

Monitor soil moisture regularly, especially during dry periods. Valerian is relatively pest-resistant, but occasionally aphids may attack new growth—spray with insecticidal soap or a strong water jet to dislodge them. Powdery mildew can develop in humid conditions; improve air circulation by thinning plants and avoid overhead watering. Slugs may damage young plants; use organic slug barriers or traps. For medicinal use, harvest roots in the fall of the second year when medicinal compounds are most concentrated. Dig carefully around the plant, lift the entire root system, wash thoroughly, and dry at temperatures below 35°C (95°F). Store dried roots in airtight containers in a cool, dark place for up to one year. Leaves can be harvested throughout the growing season for milder tea.

Understanding bolting in valerian for herbal use

Bolting in valerian refers to the plant’s natural flowering process rather than a problem as with leafy vegetables. Valerian naturally produces flower stalks in its second year of growth. This is triggered by increasing day length and warmer temperatures, typically in late spring to early summer. Unlike culinary herbs where bolting is undesirable, valerian’s flowering doesn’t reduce the medicinal quality of the roots. If growing primarily for ornamental purposes, you can deadhead spent flowers to encourage more blooms and prevent self-seeding. For medicinal use, allow the plant to complete its natural growth cycle before harvesting roots in autumn. If you wish to collect seeds, allow some flower heads to mature and collect them when they turn brown.

Why does valerian turn bitter?

• Age of roots – Roots older than three years can develop increasingly bitter compounds; harvest in the second or third autumn for optimal flavor.
• Improper drying – Drying roots at temperatures above 35°C (95°F) can cause chemical changes that increase bitterness; dry slowly in a well-ventilated, shady location.
• Soil conditions – Extremely alkaline soil can affect the chemical composition of roots; maintain slightly acidic to neutral pH for best results.
• Storage issues – Exposure to light, heat, or moisture during storage accelerates degradation; store in airtight containers in cool, dark conditions.
• Harvesting timing – Roots harvested during active growth rather than dormancy contain different compound ratios; harvest in late autumn after top growth dies back.

Companion planting for valerian for herbal use

Valerian makes an excellent companion plant due to its ability to attract beneficial insects and potentially improve the growth of neighboring plants. Good companions include:

• Roses – Valerian may help roses resist disease and attract pollinators to improve flowering.
• Tomatoes – The scent of valerian flowers can confuse pests that typically attack tomato plants.
• Brassicas (cabbage family) – Valerian attracts parasitic wasps that prey on cabbage worms and other pests.
• Fruit trees – Planted beneath fruit trees, valerian can improve fruit set by attracting pollinators.
• Chamomile – These herbs complement each other medicinally and grow well together.

Avoid planting valerian near:

• Fennel – Can inhibit growth of nearby plants including valerian.
• Aggressive spreaders like mint that might compete with and overwhelm valerian.

Seasonal calendar

• January-February: Plan garden layout; order seeds.
• March: Start seeds indoors in cooler regions.
• April-May: Direct sow or transplant seedlings outdoors after last frost; divide established plants.
• June: Apply light organic mulch; water during dry periods.
• July-August: Flowering period; deadhead if preventing self-seeding; provide extra water during heat.
• September: Collect seeds if desired; prepare for fall planting in warmer regions.
• October-November: Harvest second-year roots for medicinal use; plant in warm regions.
• December: Apply winter mulch in cold regions; clean and store tools.

Note: In zones 9-10, shift spring activities earlier by 2-4 weeks; in zones 3-4, delay spring activities by 2-4 weeks.

Problems & solutions

Common questions about growing valerian for herbal use

How often should I water valerian?
Water deeply once a week, providing about 2.5 cm (1 inch) of water. Increase to twice weekly during hot, dry periods. Container plants may need daily watering in summer.

How much sunlight does valerian need?
Valerian grows best in full sun to partial shade. In hot climates (zones 8+), afternoon shade is beneficial. Plants need at least 4-6 hours of direct sunlight daily for optimal growth.

What size container works for growing valerian?
Use containers at least 40 cm (16 inches) deep and 30 cm (12 inches) in diameter to accommodate valerian’s extensive root system. Ensure containers have adequate drainage holes.

When is the best time to harvest valerian roots for medicinal use?
Harvest roots in the fall of the second or third year when the plant has gone dormant and medicinal compounds are most concentrated, typically after the first light frost.

How cold-hardy is valerian?
Established valerian plants are hardy to USDA zone 4 (-30°C/-20°F). In very cold regions, apply a thick mulch around the crown in late fall for additional protection.

Can valerian be grown indoors?
Valerian is not well-suited for indoor growing due to its height and deep root system. However, you can start seeds indoors 6-8 weeks before transplanting outside.

How long does valerian take to germinate?
Valerian seeds typically germinate in 14-21 days when kept at temperatures between 15-21°C (60-70°F). Seeds require light for germination, so press into soil but don’t cover.