Lima Bean

Phaseolus lunatus L.

Warm-season annual
Cyanogenic if eaten raw
Nitrogen-fixing

Pet & Human Safety

People: Toxic to peoplePets: Not on the ASPCA lists as we read them

Human edibility

Edible with preparation

Edible parts

seed, cooked

Hazardous parts

seed, raw or undercooked

Preparation

must be cooked before eating; OSU Extension's own guidance: boiling in a large excess of water for more than 30 minutes removes about 80% of the original cyanide content, the most effective method; briefer boiling or steaming (5-10 minutes) still reduces levels for fresh lima beans compared to eating them raw

Hazard type

cyanide poisoning (from linamarin, a cyanogenic glycoside, released when the plant is damaged or processed)

Hazard route

ingestion, raw or undercooked seed

How complete this information is

The safety information on this page is complete as far as our sources go. That is not a statement that the plant is safe.

Toxic to pets

No ASPCA entry found.

No pet-safety verdict is given, rather than a guess. For humans, this species carries a real, sourced hazard distinct from ordinary beans: see the hazard information below: raw lima beans contain linamarin, a cyanogenic glycoside that releases cyanide, and require cooking before eating.

Patent / trademark

not applicable

Look-alike warning

Could be mistaken for ASPCA's 'Mole Bean Plant' (Stizolobium/Mucuna, velvet bean), an unrelated plant that can turn up in a keyword search for 'bean'. To tell them apart: Velvet bean (Mucuna) is a different genus and growth habit from this garden legume (Phaseolus lunatus); no further visual comparison sourced.. That ASPCA page's verdict does not apply to lima bean: mirrors the existing 'bean' guide's caution about Castor Bean Plant.

Poison control

If someone has collapsed, cannot be woken, is having a seizure or has trouble breathing, call 911 now. For any other possible poisoning, call Poison Help: 1-800-222-1222.

Emergency number source: U.S. federal law (47 U.S.C. § 251(e)(3)), read 2026-10-07.

Naturalist Lore

Historical Background & Breeding Lore

The history of this plant and its name, and how it was bred, where we have them.

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Care

Hardiness zones: Warm-season annual; needs a longer period of warm weather than common snap beans to be productive.
Water needs: moderate about 1 in of water per week (rain or irrigation), especially during blossoming and pod development
Mature size: Not addressed in the source used.
Family: Fabaceae (legume family)

Soil & Drainage

Pruning & Flush Rhythm

Feeding Schedule

How to prepare the soil, when and what to feed, and how and when to prune where that applies.

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