Comfrey Symphytum officinale
Comfrey (Symphytum officinale) is a deciduous perennial herb in the Boraginaceae family, native to Europe and western Asia. It grows 60 cm–1.2 m (24 in–3.9 ft) tall and 60 cm–1 m (24 in–3.3 ft) wide, wants part sun to part shade and moderate water, and is hardy to about -34 °C (-29 °F). Space plants about 80 cm (31 in) apart.
Plan Comfrey in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Comfrey at a glance
| Type | Perennial herb, deciduous |
|---|---|
| Family | Boraginaceae |
| Mature height | 60 cm–1.2 m (24 in–3.9 ft) |
| Mature spread | 60 cm–1 m (24 in–3.3 ft) |
| Spacing | 80 cm (31 in) centre to centre |
| Sun | Part sun to part shade, at least 4 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance moderate |
| Soil pH | 5.5–7.5 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 32 °C (90 °F) |
| Flowering | from about May for 9–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Europe and western Asia |
| Common in gardens of | 🇬🇧 United Kingdom, 🇩🇪 Germany, 🇺🇸 United States |
Is Comfrey toxic?
- People: moderately toxic
- Cats: moderately toxic
- Dogs: moderately toxic
- Parts: leaves, roots
Pyrrolizidine alkaloids can damage the liver with repeated ingestion; internal use is not advised.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Comfrey
No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.
Questions about Comfrey
- How far apart should I plant Comfrey?
- About 80 cm (31 in) apart, centre to centre. A mature plant spreads 60 cm–1 m (24 in–3.3 ft).
- Does Comfrey need full sun?
- Part sun to part shade: at least 4 hours of direct sun a day.
- How much water does Comfrey need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance moderate.
- How cold-hardy is Comfrey?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- When does Comfrey flower?
- From about May for 9–17 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Comfrey poisonous to cats and dogs?
- For cats it is moderately toxic; for dogs moderately toxic; for people moderately toxic. Pyrrolizidine alkaloids can damage the liver with repeated ingestion; internal use is not advised.
- What grows well with Comfrey?
- There is no well-documented companion pairing for Comfrey. Group it with plants that like the same sun (part sun to part shade) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- RHS Plant Finder, Royal Horticultural Society
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
- Poisonous plants of North Carolina / Plant Toolbox toxicity, NC State Extension
Notes and assumptions
- Deep taproot makes established clumps hard to remove; the true species self-seeds, so sterile cultivars such as Bocking 14 are preferred for feed crops.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Borage Borago officinalis
- Woodland forget-me-not Myosotis sylvatica
- Lungwort (pulmonaria) Pulmonaria officinalis
- Heliotrope Heliotropium arborescens
- Tree echium (giant viper's bugloss) Echium pininana
- Virginia bluebells Mertensia virginica
- Pride of Madeira Echium candicans
- Chatham Island forget-me-not Myosotidium hortensia