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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

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

Showing growth

project update by
Thursday, May 28, 2020 - 02:27

here are a couple of pictures showing the progress of two of the yam-berries that are really putting on new growth. And if I loaded the right pic there is a shot of what seems to be either blooms about to open or little tiny berries coming on. Excuse the ugly mug it was a way to show how far this vine has gone it a month. I'm right at 6 feet tall and it's over my head.

year two begins

project update by
Tuesday, April 28, 2020 - 01:50

Hi everyone,

Some of you commented that your yamberry plants didn't do much last year. That's always my experience as well. This year they should be much more aggressive, but it's on year three that they will get really large.


New plant

project update by
Monday, April 27, 2020 - 11:52

should have looked around a little before posting the last note.

New growth for the new year

project update by
Tuesday, April 14, 2020 - 11:15

Good afternoon to everyone,
I've come across a pleasant surprise this morning while checking to see if the Moringa trees were going to make it back after the near non existent winter that we had. Found three yam-berry plants coming up from the root that over wintered. I grew them out next to the Moringa trees last year and mulched both with a heavy layer of hay. I harvested a few, I believe six berries and planted them out in another spot, no sign of them yet.
Now if we could just get a little bit of rain this weekend.
Have a good one y'all,

Ready for 2nd season growing D. polystachia

project update by
Wednesday, January 15, 2020 - 03:48

Thanks for sending the bulbils to me last year! I grew them out but did not get any yamberries, nor did the vines get very tall. I managed to dig up the roots last fall after the frosts killed the vines - Since we moved to our permanent homestead and transplanted them into their new permanent garden location. Most of the roots were just a few inches long, some smaller so transplanting was very easy. I hope to see more vigorous growth this, their 2nd season. I will share updates.

Yamberry beginnings

project update by
Friday, August 30, 2019 - 02:55

I received 5 yamberries and they all grew. I planted them out and a few have been eaten by rabbits. I have protected the 2 remaining plants but they are not growing, they just seem to have stalled. Perhaps their roots are growing exponentially????

Yamberry at WPNR

project update by
Wednesday, August 14, 2019 - 03:28

Yamberry in the WPNR gardens planted 7/19. Reposted for photo.

Yamberry germination

project update by
Wednesday, August 14, 2019 - 03:25

I received the five berries and all have germinated and growing well in our fenced garden at the Winnie Palmer Nature Reserve ( They are on a temporary bamboo trellis and I will be installing a cattle panel trellis in the fall. So far so good - happy to be participating!