since you asked: apios americana, the potato bean or groundnut

copyright brushwood apios flowerJULIE, WHO GARDENS in the same Northeast area that I do, wrote in to ask: “I have been very intrigued by the potato bean since reading about it in ‘Wired’ magazine. What do you know about them? Seems they should be indigenous to our part of the world.”

copyright brushwood apios tuberJulie is referring to Apios americana, a native nitrogen-fixing legume that I was told was Apios tuberosa when first introduced to it (those are some dug-up tubers, above). It’s also called groundnut, and potato bean. And yes, they are native up into New England, but many invasive plants have shoved them out of their favored range (this older “Orion” magazine piece talks about that).

new feature: ‘since you asked’

I SPEND MANY HOURS each week trying to answer reader questions, which arrive in email and comments in such large numbers that I cannot keep up, I am sorry to admit. But I do manage to answer some, which led to this thought:

Why keep the replies hidden, between me and the individual questioner, I figure, so here we go: a new feature called “Since You Asked” that shines a light on the “best” questions—which might mean most practical, or most timely, or simply the oddest one that appealed to me who knows why.

I’ll “tag” all the entries at this link to make a stockpile of them for future reference; this is the first.

THE WIDELY adaptable groundnut has an impressive native range, in areas from temperate to sub-tropical (see the USDA range map), in Zone 4-9. It will even grow in places like cranberry bogs (growers often consider it a weed). It’s usually found in moist areas, where at least part-day sun is available.

I have seen Apios growing in the wild once or twice, and a million years ago in a friend’s garden, too; it was something she inherited, I learned, with her very old house in Connecticut, and it was just always there, climbing enthusiastically by the shed, so she went with the flow.

I say “enthusiastically,” and various Apios references say “not well-behaved,” but even though it’s a strong grower, invasives have pushed it from many former haunts, as mentioned.

If you have a spot to give it where its enthusiasm is not at issue, as in a space of its own in a fringe area, Apios (which may reach 20 feet, but probably less) is a pretty plant in flower. Vine expert Dan Long of Brushwood Nursery (who offers the plant for sale) says that at first glance, you think: red wisteria!

“I first saw this growing in the wild while kayaking with the family on Broad River in Georgia,” he recalls. “My first thought was, ‘look at that marvelous red Wisteria!’”

copyright brushwood peeled apiosmore groundnut factoids

  • Apios grows in “moist thickets,” says the Connecticut Wildflower Society, on herbaceous vines reaching up to 10 feet, flowering summer-into-fall there.
  • Early colonists, notably in Massachusetts, relied on this native plant’s highly nutritious tubers for their survival.
  • They were inspired by Native American people, who had long utilized both the bean-like seeds and the tubers, including to make flour.
  • A crude protein content of 11-16.5 percent of dry weight in tubers, and 25 to 30 percent for seeds, has been reported in various studies. (That would make the tubers as much as three times as protein-rich as potatoes.)
  • The tubers, produced like beads along strands of rhizome, can be eaten boiled, fried or roasted.
  • The plant’s foliage is one larval host for the silver spotted skipper.

(Photos from Brushwood Nursery, a.k.a. GardenVines.com, which sells groundnut plants–and I’m proud is a longtime friend and a sponsor of A Way to Garden.)

CategoriesNature vines
  1. Kathy Sturr of the Violet Fern says:

    I planted this last year (ordered from Brushwood!) in my Z4 garden in Clayton, NY – it took off beautifully and I hope to see flowers this year. I think I will try to propagate some to the Potager for a taste – or order another. I am intrigued by its higher protein content, especially now that I eat Vegan. I will also look for the Silver Spotted Skipper! Thank you.

  2. Julie says:

    I’m trying to grow more perennial food along with my vegetable garden. I’m going to have to try this. I already have the perfect spot planned for it.

  3. lynn says:

    I am so excited to learn about this native plant, here in the northeast. I hope I never stop learning about new plants, that will help me through the rest of this very long cold winter. I wonder if the snow drops are blooming, below the feet of snow, I would so hate to miss them. you know?

  4. c says:

    Here in VA with 9 new inches of snow on top of last weeks ice the snow drops ARE blooming, visibly were shoveling uncovered them and invisibly elsewhere I suspect.


    1. margaret says:

      Maybe I will go outside and dig around in the snow to catch a glimpse of something green if the snow doesn’t melt soon, C. Thanks for saying hello.

  5. Ann says:

    I learned the name of this plant as “Indian Potato”, which seems very descriptive, given it’s nutritional value. It is a great plant! One thing that also deserves to be mentioned is that it has a wonderful fragrance.

  6. Pam Geiger says:

    In my garden in NW Connecticut, it is a noxious pest. It grows up through daylilies, Siberian Iris, peonies, you name it. I’ve found tubers so imbedded in daylilies that I’ve had to discard the whole clump. I have gone so far as to remove all the plants from one bed for a year to get rid of it. A year after replanting, there it was again. The threads between the tubers are fragile and snap when you try to dig them. Roundup only gets the top growth and maybe the first tuber or so. Any small part left in the soil grows again. The vines climb up whatever is available, and drag everything down into a tangled mess.

    Our garden is 2 plus acres. It comes up everywhere except deep shade. My husband, who has been on the property since the late 70’s, fought it, then ran out of steam. I’ve been there for 9 years, and declared war on it during the very first season. Good luck to you all who have it. Those who don’t, please don’t ask me for starts. I wouldn’t give it to my worst enemy.

  7. Masha says:

    We have some, not in a moist thicket but growing up the outside of the garden fence. The flowers are beautiful but I’ve been waiting for several years for them to produce beans, to no avail. Any thoughts about why they’re not producing? I think they keep regrowing each year from the tubers.

  8. Barb says:

    Like Pam, I already have it growing here on our old farm. It’s a plant I like, but would strongly suggest that it be planted in an area of its own well-separated from other garden areas, not in a vegetable or perennial garden. It spreads unmercifully, often traveling underground for 10 feet or so in a season (I can see why farmers would consider it a weed). In my yard blooms for a couple of weeks at best, though the blossoms are striking. IMO it’s more the type of plant to grow along the edge of a wooded area where it can be enjoyed without having to fight it constantly. I think the presence of its tubers encourages voles to move in since it is present in the garden that has the worst voles (it was pre-existing under the soil when I started a new bed.) If I lived in a suburban area, I think I would plant it with a barrier, rather like bamboo.

  9. Frank Hyman says:

    I ordered several varieties of groundnuts and have planted them the same way I grow invasive native sunchokes (aka Jerusalem artichokes) in my small garden. I put them in 10 gallon nursery pots with rich soil and a good layer of mulch. Also planted some earth peas (from the Russian steppes) the same way in a pot since they like to spread also. After the sunchoke tops are killed by frost, I dump the whole pot onto a tarp and harvest all but 2 sunchoke tubers, which go back in the pots with the soil (and a couple of bricks in the bottom for ballast, so the wind doestn’ blow these tall plants over). I get an easy harvest technique without worrying about plants running loose in the garden. Expect it should work well for the groundnuts and earthpeas too, but will see how that goes.

    1. terry says:

      very sensible Frank – I might have another go at sunchokes using your method, they sure were a pest loose in the garden!

    2. Linda B says:

      I did a similar thing with the sunchokes… here in Zone 6 St. Louis area… made “pots” from 18″ chicken wire circles (about 2-3′ across) and covered the sides with black plastic. Then dug a similar sized hole about 6 inches deep in the garden, and put the wire/plastic pot in the hole and secured with a rebar type rod on 2 sides. Put newspaper on the bottom, maybe 6-10 sheets deep, filled 6 inches with compost/vermiculite/peat – whatever container medium you like – added a couple sunchokes, and filled it the rest of the way, and mulched well on top. Not quite as easy to just dump out, as Frank’s were, but still really easy, and the sunchokes were very clean, and no escapees. I kept them in the frig all winter and replanted in mid summer. These pots also work really well with carrots.

  10. Sheryl says:

    My property in the lakes region of New Hampshire has a meadow wetland with all sorts of great things growing in it, and a lot of wildlife. Last summer, I noticed there was a vine growing in the tall grasses along the edge – it was totally tangled in it. When it started flowering, I started looking it up in all my books. It took me about 2 weeks to find out that it was the groundnut ( I found the info in an edible foraging book)! I’m hoping it will come back this year because I would like to harvest and try them.

    1. margaret says:

      Interesting, Sheryl–and welcome; thanks for saying hello. Sounds like you will get the harvest you are hoping for.

  11. Nancy says:

    I am an avid gardener but have left most of the veggie stuff to my spouse because he loves it and cares nothing about anything else, all left up to me. But now I am really getting into veggies and have a million questions. Could you perhaps answer this one in your new column? Which vegetables benefit most from row covers? When do you put them on? When you take them off (or do you?), etc.

    1. margaret says:

      Hi, Nancy. I will do more on this, yes–good idea. Meantime, here are a couple of helpful stories: on using covers in general, on melons specifically. Start with that first story, because they are used for different purposes (warming things up early in the season, keeping bugs off, extending the season in fall, etc. — but with crops that rely on pollinators (like the Cucurbits) you have to take them off or at least open the “tunnels” at flowering time. More soon!

  12. SteveOh says:

    Apios americana is found in a Northern triploid form and a Southern diploid form. The northern plants tend to set bigger tubers. Triploid plants flower but produce no pods/seed. Southern diploid plants do produce seed but often produce fewer/smaller tubers.

    The plants like moist, even wet, conditions and as much sun as they can get, although they will tolerate some shade. Typical plant grow to six feet and start to brown in the heat of the summer if not well watered.

    Well drained (but moist), sandy, slightly-acidic soils seem to produce the strongest plants, but this plant will grow anywhere there is enough water and sun.

    Tubers range from slight 1/2″ swellings in the roots to 8″ giants. These grow along the length of the roots like a “necklace of pearls” with the largest tubers closest to the stem. Depending on conditions plants have been reported to produce up to 5lbs of tubers per plant, but typically yields are lower.

  13. Janean Peters says:

    If you dig deep as it can go and place contractor bag thickness 3m? Down 13″ at least and border the hole with this it may keep it from hurting lilies. Shove 12′ rebar down in the hole for vining.

  14. Susan says:

    Yes…they grow easily on our 70 acre farm in Turtletown, TN. We consider them a weedy vine the chokes our shrubs and trees. We found the tubers when we pulled the vines from the ground in an effort to clear an area of our property. No…didn’t know what they were until we took a photo of the leaves with our Picture This app. Don’t know if we will try to eat the tubers yet but that’s a possibility. Thanks fir your article which gave us some history.

Leave a Reply

Your email address will not be published. Required fields are marked *

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