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

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 (wpnr.org). 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!

yamberries harvested for distribution

project update by
Monday, September 24, 2018 - 05:17

I've harvested the aerial tubers of my best variety. Soon we'll get them in the mail to project members who live in the US. They can be fall planted or saved to plant in spring. Some are large and look quite impressive while others are small. However all are clones of the same plant so size should make no difference.

update late summer 2018

project update by
Monday, August 27, 2018 - 09:15

Hi everyone, I have some yamberries ripening up nicely. This fall I'll be able to send them out to those of you who are in the US, so we can get started with our project next spring. Eric

Commercial Production Trellis Strategy

project update by
Friday, April 27, 2018 - 05:45

Today at Nourishing Roots Farm we set up 192' of Hog Panels as trellising for Yamberries.

They are strong rigid welded wire at 16' lengths. We used wire to tie them to 6' t-stakes. Next time I will likely use 2" hose clamps for ease of breakdown.

My hope is that we can both harvest the tuber and the tubericles witht the fence in place.

Tubericle harvesting will be facilicated due to the fact that we are planting on mound beds (ridges that are 2 feet wide and 14" tall). This makes for deep pathways which we will line with tarps to collect the tubericles that are knocked off by whacking the fence and raked off with a rubber tined rake.

These are all 2nd year plants. As a part of the Experimental Farm Network programs, we will be measuring yields on this planting.

These plants survived our zone 5a winter with extended windows of -15*F and 48"+ of winter snowfall. They had 3 in of straw mulch. They are not yet sending up shoots.

I will keep all updated.