How Do I Grow Sword Beans?

Or more importantly, what are sword beans?

Think of sword beans (Canavalia gladiata) as haricot bean alternative. Both are vines and sword bean needs  a garden in a frost-free climate to grow really well.

Fancy something different for dinner?

I grow sword beans in a sunny spot in compost rich, freely draining soil. I train them on discarded fishing net attached to a sturdy bamboo wigwam. I have also grown them over  archways. The key things are: 1 to provide a sturdy support, 2 to harvest what you grow and – most importantly – 3 site your plant well within your property boundary. They crop at the tips and picking is impossible if they end up next door!

Sword bean is a short-lived tropical perennial vine. It’s sometimes described as being an under-exploited food crop. Sword beans can grow 4-7m high in one season, but they are not invasive. They can be cut back hard in autumn, but plants often die in winter. The truth is they’re not reliably perennial, even in the frost free subtropics, and since they crop best in their first year I recommend growing them as an annual, sowing them in mid-spring.

In my garden sword bean flowers are pollinated by blue-banded bees. Large pods, 30-45cm long, are produced towards the end of summer and the seed gradually swell for several weeks (they fatten much more slowly than peas). It requires practice to identify when they’re fully matured, otherwise you don’t get much food from a pod.

Fresh sword bean seed must be peeled and then boiled, or added to casseroles. Peeling removes their outer skin which contains toxins. These toxins aren’t potent, but can cause nausea if you over indulge yourself. Sword bean has a high protein content, making it a valuable food source for vegans. Note that once seed has dried, it cannot be peeled and so cannot be detoxified for use as food.

Save your best dried seed for sowing next year. I allow pods to fully dry on the vine if I want to harvest seed. Before sowing, pre-soak seed in water overnight so they are fully imbibed. Then  sow either direct where they are to grow, or individually in pots to be planted out after the seedlings have produced their first or second pair of true leaves.

Sword beans don’t have any serious pest or disease problems in Australia, but aphids may spoil flowers (reducing yield), grasshoppers tend to nibble their leaves, and leaf-cutter bees (which help pollinate sword bean flowers) sometimes use leaf pieces for making egg laying tubes.

Seed may sometimes be available through community gardens or sold commercially.

This slideshow requires JavaScript.

Jerry Coleby-Williams

10th August 2012

23 Comments Add yours

  1. Sam Eeles says:

    I just keep forgetting the name – thanks for reminding me. I need to get hold of some seeds so I can give them to the ‘green group’ at school. The kids will love growing these!

    It was good to see them ‘in the flesh’ at the Redcliffe “What’s Cooking in the Gardens” event last weekend. Loved your talk, Jerry – as always!

    Have fun with the open garden this weekend!

  2. Julie Smith says:

    I would love to grow then in Albany WA can you please let me know where i can get some seed for the Sword Bean and Aerial Potato. Will they grow in our area.

    1. You need to contact local seed networks as WA is subject to internal quarantine laws. Read my ‘where do I get seed’ blog and start there.

  3. Maerwen says:

    Hi Jeremy I am interested in trying sword beans here in the rural area outside Darwin ,when do you think I should plant and at what size should the beans be picked and how long is it necessary to boil them for before adding to stews etc . I have read they contain a growth inhibitor is this true?
    Thanks for any advice on this
    Myra

    1. Myra,
      Use the search facility in this website a read my blog on sword beans.
      Jerry

  4. Dear Jerry, I have grown sword bean (Canavalia gladiata) for several years in N.W. Louisiana (zone 8a). My seeds are huge and white. Plants are vining. They are very prolific. I would like to trade some of my white seeds for your red ones. I think seeds are easy to ship to and from Australia. Bobbie Ann Hutchins

    1. Dear Bobbie Ann,

      I can send you a few seed, my stock is currently low. But unless you can produce a US govt phytosanitary inspection certificate stating your seed is disease free it is illegal to post seed to Australia. We have strict quarantine laws and stiff fines apply.

      Regards

      Jerry

  5. Hi Jerry, i have a crop(1 vine!) fully loaded, i liked your info on sword bean, have you any more tips on harvest and possibly some recipes?, i’m in Bingil Bay, QLD, thanks Noah

    1. Noah, I haven’t posted specific bean recipes because there are so many. Harvest tips? Pick them when the pods are dry. Cheers
      Jerry

  6. Jean Santa Maria says:

    Hi Jerry, I started growing a Sword Bean plant a few months back. In no time the huge pods have flourished. Just wondering if the leaves are edible. Have you tried any recipes with them?

    1. The leaves are not edible.

  7. Charl says:

    Hi Jerry. Im in South Africa and bought 2 beans in a book shop. Our seasons are similar to Australia as we are about same distance from the South pole. Can I plant them now – early January. Regards Charl Badenhorst

    1. Hi Charl,
      Sow in spring, not midsummer. They require a long growing season to produce a decent crop.

  8. Steve says:

    I grew them years ago. Where could I find seeds?

  9. TK says:

    You say to peel the seeds. Did you mean just removing them from the pods or actually peeling every seed?

    1. You can’t peel the seed until they are removed from the pod, can you? Peel the seed.

  10. Mattie. Stewart Presley says:

    I would love to be able to get some of these seeds. Can you tell me how I can get some of these please?

  11. Dove Stackhouse says:

    I have the white seeded variety and the seeds are close to maturity but the eyes have not established color, we have had a couple of light frosts and they have kept going but we are getting a hard freeze soon. The pods are still green can I harvest now and have viable seed? I am in zone 7b ne Alabama USA

    1. The thick, tough pods protect the seed from a frost, providing adequate insulation against one of -3C. With this bean it is wise to allow the pods to mature as fully as possible before harvest. You will have to judge the timing, but ideally try to wait until the pods are fully brown (or as close as you can risk it) by which time they will be ready to open.

  12. Can we sow seed directly or should we remove thick skin on sand paper before sowing. Please let me know

    1. Never interfere with the seed coat if you wish to grow this plant. Pre-soak seed in water before sowing when it is fully imbibed.

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.