Cooking Poisonous Plants Vegetables

Are Bean Seeds Edible?

Bean seeds come in a wide range of colors and sizes. Photo:

Question: I was a bit slow harvesting my green and yellow beans this summer and many dried out and went to seed. I’ll use some as seeds for next year’s crop, but since I have a lot of them, I wondered if the seeds were edible.


Answer: Yes, the dry seeds of the common bean (Phaseolus vulgaris) are edible. In fact, they have been used for thousands of years for soups, chilies, stews, etc. Boston baked beans, a classic dish I’m sure you’ve eaten many times, are, in fact, made from dry beans.

Dry beans need to be soaked and boiled before being eaten. Photo:

That said, it’s important to prepare dry beans properly, including soaking them in water for at least 5 hours (discard the water used to soak them) before boiling them for at least 15–20 minutes (the US FDA recommends 30 minutes).

This is because the dry seeds of all types of common bean contain phytohemagglutinin (PHA), a toxin that is destroyed by prolonged cooking. It’s not all that rare that people end up in the hospital after consuming soaked beans that they thought were cooked. Interestingly, rats seem to know dry beans are poisonous, as they will raid stores of cereals and other crops, but never touch dry beans.

The level of phytohemagglutinin varies considerably from one type of bean to another and it is generally quite low in beans harvested from green and yellow beans, but very high in kidney beans, both red and white. Even so, proper soaking and cooking are recommended for all beans, regardless of the color of the seed.

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

1 comment on “Are Bean Seeds Edible?

  1. Some dried beans from the supermarket can be grown too.

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