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Yamberry Yields

Chinese yam (Dioscorea polystachya) produces small aerial tubers ("yamberries"), which grow on the vine like berries but are in fact tubers. They are very good cooked starchy vegetables and a potential market crop and no-till perennial staple food for temperate climates. It takes several years until the yields really kick in, but data on those yields is unavailable. Let's generate that information together.

The goal is to measure the yields of yamberries on vines 3, 4, and 5 years old.

Each participant should build a trellis for easy harvest of the aerial tubers. When they are ripe you should have easy access to place a tarp or blanket under the trellis. Shaking the vines will result in almost all of the yamberries falling to the tarp for easy collection. Trellises should be fairly sturdy as the vines can grow 15-20 feet high and are robust. Report how many square feet of ground your trellis will cover. Mine will be a horizontal cattle panel 4x16', laid flat at 5' high, supported by metal t-posts.

After you build your trellis, plant your yamberries and care for them until they are mature beginning in year 3. At that point, harvest and weigh your aerial tuber yield each year for years 3, 4 and 5. After weighing them you can eat them! Boil them for 10 minutes and add salt, they taste just like new potatoes. Or add them to stews in the last 10 minutes or so. After the year five harvest, if you like, you can dig up the "mother tubers" underground. They are brittle but large and delicious.

I can send yamberries this fall to folks in the US, or you can order them from Oikos Tree Crops, that's the source of the variety with the largest aerial tubers that I am aware of.

Researcher background
I've collected lots of data from other authors on the yields of perennial staple crops, collected in The Carbon Farming Solution. I'm curious about this particular crop as it fills an important niche for cold climates - perennial starchy no-till staple crop.
Are you seeking volunteer growers or other types of volunteers?
Yes, seeking volunteer growers
How many volunteers do you need?
What will you ask volunteers to do?
Build a trellis, care for the vines, harvest and weight the crop for years 3, 4, and 5. Report the area of your trellis so we can calculate the yields in pounds per square feet, and ultimately convert to kg/sq meter.
Other requirements of volunteers?
Participants should be in a temperate climate, USDA zones 4-8. Dioscorea polystachya is considered weedy in some areas and considered highly invasive in Tennessee and Kentucky. It is not illegal to grow anywhere in the US as of 2018. Please be thoughtful about where you plant it if this is of concern in your area. If your region is dry, you'll have to irrigate.
Is this a multi-year project?
Can volunteers expect to be able to keep some germplasm (seeds, bulbs, cuttings, spores, etc) at the close of the project?
Yes, of course
Researcher Location

United States

Project Updates

New to project

project update by
Thursday, March 7, 2024 - 09:44

Hello network! Is this project still active? If so, I would love to get started on growing this fascinating crop. Let me know if you have tubers you can send my way.


Interested in joining the project

project update by
Thursday, September 22, 2022 - 07:05

Hello dear folks,
love this project! Unfortunately Kenneth Asmus from Oikos tree crops does not grow the big air potatoes anymore and also he kinda discontinued his nursery, only some seeds still going. So if anyone has a few big aerial tubers to share that would be awesome! I am situated in Germany but have a possibility to get the plant material here via a befriended botanic garden. Would love to assess yields and improve them if possible over here.

Yamberries wanted

project update by
Saturday, January 29, 2022 - 08:08

I would like to experiment this plant. I am in North Central Texas, Zone 7. I would appreciate if any one would share 5 or more yamberries with me. I am happy to pay for shipping. Thanks.

first harvest

project update by
Saturday, October 9, 2021 - 07:08

Just completed my harvest. It's year 3, the first year of decent yields. Based on past experience I expect the yields to be higher in year 4 and even higher in year 5, and then more or less stabilize. I collected all the yamberries from my 1 square meter collection area under the trellis. After removing debris and washing them, they weighed 1.9 kilograms (4.3 lbs). That's about 1/2 or 1/3 of what potatoes would yield. So about what I expected. I'm very excited to see what future years will produce - and to see what yields all of you report!

Growing Strategy and Bulbil Replacement

project update by
Wednesday, September 8, 2021 - 05:05

Greetings All.

2 things: I want to share how I mass produce large tubers for sushi markets and I am requesting bulbils from project members.

I lost the small lot of bulbils Eric Toensmeier sent out from frost penetrating the soil. I was hoping to get some again, I am willing to pay and am looking for up to 5 lbs. Please contact me if you are willing to share your harvests.

I have attached a photo showing how I produce the tubers for commercial markets. Obviously when harvesting these deep penetrating and easily broken roots it becomes quite a chore. So I started experimenting with methods to produce long straight tubers that did not require deep laborious digging. I have attached a slideshow showing my process. If anyone is interested then feel free to contact me with questions.

first year to measure yields!

project update by
Wednesday, April 14, 2021 - 04:06

Hello everyone,

I hope you are all healthy and well. We are now in year three, and our yamberries should be having their first proper yield this year, though I expect they will grow larger for the next two years (we'll measure them in 2022 and 2023 as well).

When your yamberries are ripening this fall, here's what I'd like us all to do. Build a little wooden frame 1 meter by 1 meter square (39.5" x 39.5"). Place it under the trellis with a tarp or towel under it, and shake down all of the yamberries. Weight them and let me know the total. Then you can eat them! I'll write as the time approaches with more details.

Do let me know if your yamberries died, or you had to move, or for some other reason you don't expect to have yields to report this year.

Thanks everyone!



project update by
Tuesday, April 13, 2021 - 11:28

Hello all, new to the network 😊 Very exciting concept! Is this project still active? Would love to participate, I'm in zone 4a, latitude 60 (Alaska), snow is starting to melt here so it would be great get my hands on some yamberries quick, as we have a pretty short, sunny growing season here. Thanks!

Ready to plant

project update by
Thursday, March 18, 2021 - 06:03

About 1.5 pounds of yam berries are ready to put into the dirt.
They have been on the shelf in the pantry since last fall.
Should be about ready weather wise, here we usually get our last frost
sometimes in mid to late March.

first harvest

project update by
Monday, September 21, 2020 - 05:33

Looks like many of you are having your first, small-scale harvest from second-year plants. They are ripe when they fall - try laying a blanked under them and shaking them down. Plant some if you like but try cooking some. I boil them for 10 minutes and add salt and sometimes butter - they are really quite good! Next year we'll get our first heavy yield and we can start collecting data! Meanwhile hope you enjoy your vines. Eric

Year Two

project update by
Monday, September 21, 2020 - 12:21

I have just returned to work after being furloughed from my job since March and unable to weed around the vines. They didn’t seem to mind the weeds and have produced a few handfuls that I replanted. A new cattle panel trellis will be installed next year. So far they seem to have multiplied since year one.

Yam berry harvest

project update by
Friday, August 28, 2020 - 09:55

Picked 10.5 oz of berries from one plant a few minutes ago. A lot of them from off the ground. Took 5 of the biggest ones to make an ounce, probably picked and picked up 100 or so.
Laura blew through here yesterday and pretty much wiped the garden out. Several of my berry vines are wind burned very badly. Some may not make it.
Wish that I could get pictures to upload.

Red yamberries

project update by
Thursday, August 27, 2020 - 03:05

Was harvesting off some of my yamberry plants, and found these red ones. Has anyone else gotten red yamberries? They are cranberry red. Placed some of the green ones next to them just to show the contrast, hope It's clear.


project update by
Tuesday, July 14, 2020 - 07:12

This really stinks.
Can anyone tell me what I've done wrong?
I've chosen files and my machine says that it is uploading, but then nothing.


project update by
Tuesday, July 14, 2020 - 06:57

One of the vines is really going crazy

fat fingers

project update by
Saturday, July 4, 2020 - 11:08

I've got to learn to stop pressing buttons to get this machine to go faster.
It results in broke up posts on my part.
I hope that this does finally show the pictures that I've tried to post. I'm getting excited to
tell of how well some of these plants are starting to do.
If this posts pics twice, excuse me.
I have not figured out if there is a way to edit my posts or not.

Lot of berries starting to show up

project update by
Saturday, July 4, 2020 - 10:59

Of the eight vines that I have growing there is one that is really showing off.
It was the first one to sprout this spring and is the strongest grower by a long shot.
The other vines are starting to show some promise as well