How to Grow Valerians UK | Regional Planting Calendar

Regional Planting Calendar

Region	Sow
Southern England	early March to mid April
Midlands	early March to late April
Northern England	mid March to late April
Scotland	late March to early May

Southern England - detail & sources

PFAF: sow in spring in a cold frame; taken here as a spring window for southern England. RHS rates the species H4 (-10 to -5C), hardy through most of the UK.

Midlands - detail & sources

Same spring sowing window as southern England, shifted about a week later for a cooler start -- RHS's H4 rating covers Midlands winters fully.

Northern England - detail & sources

Sowing window shifted about two weeks later than southern England for Northern England's cooler spring -- RHS's H4 rating (-10 to -5C) is a genuine, if modest, limiting factor in a harder winter this far north.

Scotland - detail & sources

Sowing window shifted about three weeks later than southern England for Scotland's cooler, later spring. Honest caveat: RHS's H4 rating means severe Scottish winters can occasionally test this species' limits outside a sheltered spot.

Quick Facts

Factor	Value
Sunlight	4-8 hours direct sun
Minimum survivable temp	-10C
Drainage	Moist but well-drained (RHS); PFAF: prefers a rich, heavy loam in a moist site, but succeeds in ordinary garden soil across light, medium or heavy textures.
Lifecycle	RHS: a clump-forming herbaceous perennial, rated H4 (-10 to -5C) -- hardy through most of the UK. Cut back to ground level in autumn.
Edible parts	leaves, seeds, root

At a Glance

Growth Stages

Stage	BBCH	Notes
Sowing	0	PFAF: sow in spring in a cold frame, only just covering the seed since it needs light to germinate; prick out seedlings once large enough to handle. RHS separately notes division in spring or autumn as an alternative.
Establishment	3	RHS: generally pest-free and disease-free once established. PFAF adds a genuinely practical caution: cats are strongly attracted to this plant, similar to catnip, and can damage or destroy young growth.
Flowering	6	RHS: fleshy stems topped with rounded clusters of small pink or white flowers in summer -- PFAF separately notes the plant is noted for attracting pollinators.
Root harvest (year two)	8	PFAF: the medicinal root is only harvested from 2-year-old plants, dug in autumn once the leaves have died down -- a genuinely patient crop, not a same-season harvest.

Harvest & Storage

When to pick: PFAF: dig the roots of 2-year-old plants in autumn once the leaves have died down.

Storage

PFAF: use fresh or dried -- fresh root is about three times as effective as root dried at 40C, and drying temperatures above 82C destroy the active principle, so keep drying gentle and cool.

Pests

Cats

Felis catus

PFAF: cats are very fond of this plant, similar to their attraction to catnip, and can destroy it.

Valerian, a Hardy Perennial Grown for its Root

A clump-forming herbaceous perennial

RHS: a clump-forming perennial rated H4, hardy through most of the UK, reaching 1-1.5m tall.

Flowerheads opening in summer

RHS: fleshy stems topped with rounded clusters of small pink or white flowers, blooming through summer.

Aromatic pinnate leaves

RHS: aromatic, bright green, pinnate leaves are one of the plant's most recognisable features.

At home in damp meadows and scrub

PFAF: found growing wild in grassland, scrub and woods, on dry or damp soils.

A magnet for pollinators

PFAF: noted for attracting wildlife, particularly pollinators, to its rounded flower clusters.

The source of the medicinal root

PFAF: the root of 2-year-old plants is what's harvested for medicinal use -- dug in autumn once the leaves above have died down.

A tall, upright habit

PFAF: a medium-rate perennial reaching about 1.5m (5ft) tall by 1m (3ft3in) across.

Thrives in sun or partial shade

PFAF: thrives in full sun or partial shade, doing well even in light woodland.

A genuinely low-maintenance herb

RHS reports valerian as generally pest-free and disease-free -- a real, low-fuss plant for a wildlife or cottage garden border.

References

1. Plants For A Future (PFAF) - Valeriana officinalis

   Habitat: grassland, scrub, woods, on dry or damp soils, avoiding acid soils. Hardiness: USDA zones 4-8, UK zone 5. Soil: light/sandy, medium/loamy or heavy/clay, mildly acid/neutral/basic, prefers a rich heavy loam in a moist site but succeeds in ordinary garden soil. Sun: full sun or partial shade, does well in light woodland, cannot grow in deep shade. Moisture: prefers moist soil. Size: perennial to 1.5m (5ft) by 1m (3ft3in), medium growth rate. Propagation: sow seed in spring in a cold frame, only just covering it since it needs light to germinate; prick out when large enough; division in spring works best, pot up smaller divisions in light shade until established. Medicinal use: roots of 2-year-old plants harvested in autumn once leaves die down, used fresh or dried -- fresh root about 3x as effective as root dried at 40C; temperatures above 82C destroy the active principle. Edible use: seeds parched and eaten; essential oil from leaves/root used as flavouring in ice cream, baked goods, condiments; leaves also used as a condiment; plant used in moderation as a herbal tea. Safety: prolonged medicinal use can lead to addiction, course of treatment should not exceed 3 months; adverse effects include headaches (rare), giddiness, nausea, excitability and agitation; avoid combining with other sedatives or before driving; should not be prescribed for patients with liver problems. Wildlife: cats are very fond of this plant and can destroy it; the dried root also attracts rats (historically used for rat-trapping); noted for attracting pollinators.

2. Royal Horticultural Society - Valeriana officinalis (common valerian)

   Hardiness H4 (-10 to -5C), hardy through most of the UK. Soil: clay, loam; moist but well-drained; pH neutral, acid or alkaline. Position: full sun or partial shade, south- or west-facing. Exposure: sheltered. Size: height 1-1.5m, spread 0.5-1m, 2-5 years to maturity. Propagation: seed in containers, softwood basal cuttings in spring, or division in spring or autumn. Pests/diseases: generally pest-free and disease-free. Garden use: cottage gardens, wildflower meadows, city gardens, coastal settings, wildlife gardens, flower borders. Maintenance: cut back to ground level in autumn. Description: clump-forming perennial, aromatic bright green pinnate leaves, fleshy stems topped with rounded clusters of small pink or white flowers in summer. Common names include "medicinal valerian" and "Hercules' all-heal".

2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.