Bogbean (buckbean) Menyanthes trifoliata
Bogbean (buckbean) (Menyanthes trifoliata) is a deciduous perennial flowering plant in the Menyanthaceae family, native to Bogs and pond margins across the Northern Hemisphere. It grows 15–30 cm (6–12 in) tall and 50 cm–1 m (20 in–3.3 ft) wide, wants full sun and high water, and is hardy to about -38 °C (-36 °F). Space plants about 45 cm (18 in) apart.
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Bogbean (buckbean) at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Menyanthaceae |
| Mature height | 15–30 cm (6–12 in) |
| Mature spread | 50 cm–1 m (20 in–3.3 ft) |
| Spacing | 45 cm (18 in) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | High; drought tolerance none, waterlogging tolerance high |
| Soil pH | 4–7 |
| Cold hardiness | About -38 °C (-36 °F) once established (roughly USDA zone 3) |
| Heat stress | Likely above about 28 °C (82 °F) |
| Flowering | from about May for 4–6 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Moderate |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Bogs and pond margins across the Northern Hemisphere |
| Common in gardens of | 🇬🇧 United Kingdom, 🇮🇪 Ireland, 🇩🇪 Germany, 🇫🇷 France, 🇳🇱 Netherlands, 🇵🇱 Poland, 🇸🇪 Sweden, 🇳🇴 Norway, 🇷🇺 Russia, 🇯🇵 Japan, 🇨🇦 Canada, 🇺🇸 United States |
Is Bogbean (buckbean) toxic?
- People: mildly toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
- Parts: leaves, rhizomes
Intensely bitter; large amounts may cause vomiting and diarrhoea.
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 Bogbean (buckbean)
No well-documented helpful pairing. Group it with plants that like full sun and high water.
Questions about Bogbean (buckbean)
- How far apart should I plant Bogbean (buckbean)?
- About 45 cm (18 in) apart, centre to centre. A mature plant spreads 50 cm–1 m (20 in–3.3 ft).
- Does Bogbean (buckbean) need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does Bogbean (buckbean) need?
- High water. Drought tolerance is none and waterlogging tolerance high.
- How cold-hardy is Bogbean (buckbean)?
- It tolerates about -38 °C (-36 °F) once established, roughly USDA zone 3.
- When does Bogbean (buckbean) flower?
- From about May for 4–6 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Bogbean (buckbean) poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people mildly toxic. Intensely bitter; large amounts may cause vomiting and diarrhoea.
- What grows well with Bogbean (buckbean)?
- There is no well-documented companion pairing for Bogbean (buckbean). Group it with plants that like the same sun (full sun) and water (high).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society
- Wildflowers and meadows, Plantlife (UK)
Notes and assumptions
- A pond plant: keep it in water all year and plant it in a basket of heavy loam, never rich compost.
- Bean-like, three-part leaves on creeping stems at the water’s edge, and pink-budded white stars with fringed, hairy petals, unlike any other British wild flower. Its bitter leaves have been used in place of hops.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
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- Sunflower Helianthus annuus
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- English lavender Lavandula angustifolia
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- Cosmos Cosmos bipinnatus
- Purple coneflower Echinacea purpurea
- Foxglove Digitalis purpurea