Japanese Mountain Yam

Dioscorea japonica  IMG_5998Another variety of “Wild Mountain Yam”. Very similar to the Chinese Yam, except this variety produces tubers that grow more like sweet potatoes. Instead of growing straight down like the Chinese Yam, these grow more horizontally and are somewhat easier to dig. They also can produce multiple tubers. This variety may be what is known in Japan as ichoimo (5 fingers)

Once you receive the bulbils, I would plant in 3″ or 4″ pots with regular potting mix. Plant at a depth of 1/4″. Once plants begin vining they can be set out into garden. The bulbils can also be planted directly into garden soil IMG_5978but I have better success starting as a transplant. Space plants 2 foot apart. I would also highly recommend planting into a tall raised bed. These tubers can get very large and are quite fragile. Having loose soil around the tubers makes digging easy. Tubers should be dug 2nd year for best size and quality. This plant also requires some type of trellis to grow on. In the fall, the vines will be covered with tiny bulbils which can be harvested and replanted.

These are excellent sliced thinly and fried like a potato chip. They are also excellent baked IMG_6009and roasted. In Japan, mountain yam (Jinenjo) is most commonly eaten raw as “tororo”. The yam is peeled and then grated into a miso broth and served over cooked rice or barley. They can also be stored over the winter like an Irish potato. This is truly one of the few perennial staple crops for the north and worthy of greater attention!

*As a side note. In ancient Japan, women were forbidden to eat jinenjo, for fear they would become too powerful and acquire too much strength!



37 Responses to Japanese Mountain Yam

  1. Michael Buchanan says:

    As a student of oriental medicine and gardener it is good to see that you have both these varieties of mountain yam. I am looking forward to get to know and work with the fresh herbs.
    I like that you seem to be very interested in older and probably wilder varieties – such as the Umbria wild peas and black peanut – I think we will be healthier if we eat the wilder types of food and less hybrids.
    Also thanks for the Intro to Camelina- sounds very nutritious – How did your Piteba mill work out?



    • John Sherck says:

      Hello Michael,
      I have a limited understanding of how to use medicinal herbs, but I have planted a number from seed. Primarily anti-viral and and anti-bacterial!
      My primary interest is in open-pollinated seed! I believe farmers and gardeners should be able to save their seed. Secondly, I give heritage and
      ancient grains a primary place on my farm. I believe, that these cultivars have the genetics we need, to deal with climate “weirdness” as well as
      offering a great diversity of flavors and uses.
      Camelina is a fantastic crop for the north. Easy to grow and productive. My understanding, is that seed availability for camelina is being suppressed
      by proprietary, Big AG!
      My Piteba Press works, but it is finicky! Oil content of the seed and ambient temperature when processing, are crucial! You will have to really know
      your seeds oil/moisture content. Do not press in a cold room/porch! I believe the Piteba Press should be improved for the next GEN.

      John Sherck

  2. Matt says:

    More Please!
    Any chance you’ll have more during the summer?

  3. Theodore Davey says:

    Amazing. You advertised five tubers, but sent six. I farm in Northern Nevada (the Great Basin Desert), so probably not much like Indiana, but I just can’t resist a possibility, especially in the (I, you, claim) emerging realm of perennial edibles. So, having no clue about how to proceed, I went conservative and “trialed” all 6 tubers in a fast food container on moist paper towels. Four of them sent out a little stem sprout, and when something that might be a root appeared, I potted them. The two unsprouted tubers, I potted them up also, thinking oh well, “germination” percentage of 67% ain’t so bad. Well, all six are alive and well, happily basking near a south facing window. The leaves (one per tuber so far) are beautiful and I’m looking forward to success with what may be the only J. Yam population in the State of Nevada. Thanks for your pioneering spirit, and your willingness to share it with us.

    • John Sherck says:

      It should be interesting to see how these plants do in your region. What are
      the winters like? I assume your summers are quite hot and dry.

      • Theodore Davey says:

        Summers are typically hot and dry, beginning on a date which is totally upredictable. It is a common experience here for apples and peaches to satisfy their cold degree days requirement, flower, set fruit, and lose the whole crop to a late frost. Grapes do better, and primocane raspberries do the best.

        I am about to declare summer and plant out three of the yams, keeping three in reserve in case of disaster. Planning to trellis on cattle panel. Also going to trellis an heirloom pumpkin (1) grown from a 10-year old seed given as a last bequest by a deceased friend.

        Great to discover your website. An honor to participate.

  4. Matt says:

    How tall of a trellis would you suggest? Is it ok to let them weep after reaching six feet or so?

    • John Sherck says:

      I have used bamboo teepee type structures and basic hortonova (6 1/2′ mesh trellis) strung between
      T-posts. Both seem to work fine. If they get to the top and fall over, it is ok. Main thing would be
      that whatever you use should be high wind proof. Trellising makes harvesting the air potatoes, for
      propagation, easy!

  5. Mário Lopes says:

    Oh! I’m amused just just by reading your comments! I’m starting experimenting in a small land(about 700 square meters) I borrowed from some friends. I’ve been using and producing good foods for many years in different parts of the world. Now I’m living in Portugal where I was born actually. I just bought some wild yam from a Chinese store and it started spouting, I’m happy as I see the possibility to grow my own! I’ll read again trough your page and see what comes out next. I’m still cleaning and preparing the land, when I start sowing probably I’ll ask some from your things if available.

  6. Jim says:

    I’ll *definitely* be ordering some Japanese Mountain Yam from you in March 2017!

    Since this is the first time I’ll be ordering from you, is there somewhere I can sign up to be notified when your plants are available for order or should I mark my calendar to start checking your site in late January?


    Let me know when it back in stock, please.
    Thank you!

  8. Theodore Davey says:

    Bummer indeed. I wanted to try again in a slightly less sun-drenched part of the garden.

    Maybe 2018?

  9. Juli says:

    Hi John, thanks for the great seeds last year. I am getting bulbils on my Chinese Mountain Yam now, cold weather will be here end of October. Do you suggest planting them now or holding over winter? They seem to dry out quickly so perhaps they need special conditions in storage? I only have one plant got to keep them going (I foolishly waited too long to plant most of the bulbils you sent). Plant looks good! Thanks!
    Juli in Mass.

    • John Sherck says:

      Hello Juli, I have tried overwintering in the fridge in containers with holes poked in them. I did get some mold on a few. The next season I stored
      them with my potatoes in the cellar. That also worked, although a few dried out. This last fall, I allowed a lot of them to fall onto the ground. In
      the spring, I had countless hundreds of little plants. These can become invasive if you are not careful. I would suggest leaving a few in the ground,
      either under some light mulch or in the soil (1/4″ deep). You may be very surprised how well they survive the winter.

  10. Juli says:

    Thank you for the info and for introducing us to these rare crops. Can’t wait to see what you’re offering for next spring.

  11. Evan says:

    I am anxious to know when you will have more. I love these little gems, and their ecological benefits as solid cultivators are not to be understated.

  12. Jason says:

    I’m a little late to the party. These yams sound awesome! and they are hard to find. Hope you’ll be offering them again sometime.

  13. Karlie Baum says:

    I would very much like to have bulbils if you get them in again!!! I would love all the varieties of japanese yam you have!

  14. Linda Trujillo says:

    I just found your website, will you have any bulbils this spring? Hope I’m not too late for this year.

  15. Jennifer Youngberg says:

    so just to clarify, If we plant this year, we should not harvest the yams until next year in the fall? (fall 2020)? I got 2 Bulbils at the Goshen Farmer’s market.

    • John Sherck says:

      I would let them go until the second season before digging. You should get a few air tubers the first season in the fall and especially the second. That way you will have a continual supply. If you wait longer than 2 years the tubers can get very long and difficult to dig.

  16. Jean Hartney says:

    Will you ship to Hawaii? We love it raw with me home made natto.

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