Kersting’s groundnut (doyi) Macrotyloma geocarpum
Kersting’s groundnut (doyi) (Macrotyloma geocarpum) is an annual vegetable in the Fabaceae family, native to West Africa (Benin, Togo, Ghana, Burkina Faso, Nigeria). It grows 10–25 cm (4–10 in) tall and 30–50 cm (12–20 in) wide, wants full sun and low water, and is hardy to about 10 °C (50 °F). Space plants about 25 cm (10 in) apart.
Plan Kersting’s groundnut (doyi) in your garden →
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Kersting’s groundnut (doyi) at a glance
| Type | Annual vegetable |
|---|---|
| Family | Fabaceae |
| Mature height | 10–25 cm (4–10 in) |
| Mature spread | 30–50 cm (12–20 in) |
| Spacing | 25 cm (10 in) centre to centre |
| Sun | Full sun, at least 7 h of direct sun a day |
| Water | Low; drought tolerance moderate, waterlogging tolerance none |
| Soil pH | 5–7 |
| Cold hardiness | About 10 °C (50 °F) once established (roughly USDA zone 12) |
| Heat stress | Likely above about 40 °C (104 °F) |
| Flowering | about 6–9 weeks after planting, for 4–7 weeks |
| Days to maturity | About 120 days from planting |
| Wind tolerance | Low |
| Pollinator value | Low |
| Edible | Yes: seeds (cooked; underground pods) |
| Native to | West Africa (Benin, Togo, Ghana, Burkina Faso, Nigeria) |
| Common in gardens of | 🇳🇬 Nigeria |
Is Kersting’s groundnut (doyi) toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Not poisonous when cooked like other dry beans.
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 Kersting’s groundnut (doyi)
Good neighbours
- good With Sweet corn: "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils. Evidence C
Keep apart or take care
- caution With Alliums (onion family): Onions, garlic and leeks are said to stunt beans and peas (allium root exudates may reduce nodulation). Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Alliums (onion family): Beans and peas are traditionally kept away from onions, garlic and leeks. Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Fennel: Fennel is reported to suppress beans and peas growing next to it. Evidence C
Questions about Kersting’s groundnut (doyi)
- How far apart should I plant Kersting’s groundnut (doyi)?
- About 25 cm (10 in) apart, centre to centre. A mature plant spreads 30–50 cm (12–20 in).
- Does Kersting’s groundnut (doyi) need full sun?
- Full sun: at least 7 hours of direct sun a day.
- How much water does Kersting’s groundnut (doyi) need?
- Low water. Drought tolerance is moderate and waterlogging tolerance none.
- How cold-hardy is Kersting’s groundnut (doyi)?
- It tolerates about 10 °C (50 °F) once established, roughly USDA zone 12. As an annual it is usually planted out after the last frost.
- When does Kersting’s groundnut (doyi) flower?
- About 6–9 weeks after planting, for 4–7 weeks.
- Is Kersting’s groundnut (doyi) poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not poisonous when cooked like other dry beans.
- What grows well with Kersting’s groundnut (doyi)?
- "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils.
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- Lost Crops of Africa, vol. I Grains (1996), II Vegetables (2006), III Fruits (2008), National Research Council, National Academies Press, Washington DC
- PROTA4U: Plant Resources of Tropical Africa, PROTA Foundation, Wageningen
Notes and assumptions
- Like the peanut, the flower stalks push the young pods into the soil to ripen. A prized, expensive festival food in Benin and Togo, now grown by few farmers and at risk of being lost.
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
- Bush bean Phaseolus vulgaris
- Garden pea Pisum sativum
- Sweet pea Lathyrus odoratus
- Runner bean Phaseolus coccineus
- Broad bean (fava) Vicia faba
- Lima bean Phaseolus lunatus
- Cowpea (black-eyed pea) Vigna unguiculata
- Yardlong bean Vigna unguiculata subsp. sesquipedalis