I recently planted three Chinese Mountain Yam plants (Dioscorea batatas) from Oikos in a large potato grow bag in a protected interior spot of my Vermont garden. I am looking for some advice on overwintering the plants.

Has anyone successfully overwintered them in zone 4b? If so, what kind of protection did you use, if any? If I need to, I can move the grow bag into my garage (usually a bit above 32 in the winter as it is under our radiant heated bedroom floors), but my preference would be to leave the plants in situ if they will survive. Presumably, I'll cover them in a deep bed of straw and maybe even build a structure on top of that. I am thinking of digging up one of the plants and bringing it in as insurance, plus I can save some of the air tubers for replanting, but I've heard the air tubers are bigger on older vines so I'd prefer to let the plant grow for multiple seasons.

Another question: when the foliage comes up on the Spring, is it frost hardy?

Thanks in advance for any advice!

Hey, Jeff, welcome to Permies.

Unfortunately I don't know anything about your question. But me replying here will bump it back up to the top and give you a second chance for somebody who knows the answer to spot your post. Hope it works!

Jeff Lubell : This is a little out of my wheel house but you might try contacting Fellow Member Rebecca Norman Who lives/works in Lahdakh in the Indian Himalayas at 10,000' .

It is possible that she may have run into this yam variety before . Gool lock and good hunting For the Good of the Crafts Big AL

Thanks. Glad to be a forum member. I'll look forward to input from forum members. Jeff

I haven't gotten around to ordering this one yet, but it's been featured by The paradise lot duo, they are in I think zone 5 and had it growing on their deck. I think it's supposed to be winter hardy, maybe call up Oikos?

Jeff,

I'm growing dioscorea batatas in Denver (zone 5). From what I've read, it can't survive below a zone 5 winter, but you can get a good crop in one season.

After germinating and growing them up a little, I transplanted them into apx. 3 gallon pots and put them around a tree to grow up into. We're on solid clay here - picture daikon radishes growing out of the ground instead of into it, so I figured that taking the root out of a pot would be a lot easier than digging. I did some research on them and the first year they will produce a very nice size root that stores well. You can cut off the top of the root and replant it in the spring. This method won't get you the HUGE roots, but it may still be worthwhile. I just read today that someone harvested the aerial tubers and ate them like new potatoes. Maybe I'll just bring a few potted ones into the garage to winter over and see what happens....

This is the second year that I've grown them and the first year to try this method. I hope it works well. The first year was in a raised bed near the porch and the poor thing got sunburned here in Denver, which is why I'm trying the partial shade under a tree method. I'd be interested in your results also.

Thanks for the input, Robin. I am growing these primarily for the small air tubers rather than for the larger yams (though I will eat them too when they get big enough) so I like the idea of storing and replanting the larger tubers. I don't know why I didn't think about that.

I have three plants, so my latest thinking is: (a) leave one outside and cover it well; (b) dig up one, pot it, and put it in the garage to overwinter around the freezing point; and (c) store one larger tuber for replanting next year.

Did you overwinter your plants last year and if so, when did they emerge? Were they frost sensitive when they emerged or frost hardy? Thanks!

Jeff,

My first try at growing these didn't work due to heat and sun killing the plant so this is the first year that I'll be growing them in pots under the tree. Assuming that some do well, I'll try the overwintering technique. I like your plan to try storing them three ways.

I'm not sure about frost hardiness. One reference says to put them out in early spring and another says late spring. If you find out anything more definitive I'd be interested. We have 2-3 good months of decent springy/snowy/you-name-it weather so I'd hate to lose all that growing time if they're frost tolerant.