Yams in Melbourne - Japanese or Chinese Yams are the easiest to grow

White Yams Dioscorea alata are very beautiful plants and I've been working out the best way to grow them down here at Lat 38 south. All this time though I've also been growing, but kind of neglecting, another Yam that is in fact a lot easier to grow than White Yam, Chinese or Japanese Yam, Dioscorea opposita or polystachya (depending on the source). These are the long, white yams sold in various markets and which I embarrassingly once mistook for Cassava and used for a student prac.
 
Chinese Yams have smaller more delicate leaves than White Yams and in that way their beauty is more subtle. The actual yams are very long and skinny and probably best grown in deeply dug, raised beds if you are serious about production. See this man taking them out of a purpose-built planter box:

Their main virtue in terms of ease of cultivation is their cold tolerance, more specifically their ability to overwinter in cold, shaded, moist soil. I have pretty much proved now that White Yams can't do this in Melbourne and will rot if not lifted and stored. They will will only re-shoot in spring in a free-draining, open sunny site (more on that in another post).

But Chinese Yams ride through it all with no problems and do not rot at all. Their foliage also persists long into winter and still looks good too even after a few cold nights. This is a plant that deserves to be grown more commonly as a deciduous herbaceous climber with the added bonus of edible tubers.At present they are not sold in nurseries and you can't buy them from such pioneers of alternative edibles as Greenharvest or Isabella Shipard. I'll work with my students at Burnley this year to see if we can change that in some way.

If you're from southern Australia have a look at the following video of a Chinese gentleman growing a commercial yam crop in the (relatively) cold Otway Ranges south-east of Melbourne. Quite extraordinary, I'd love to meet this guy.

Finally, a shot of Chinese Yam foliage from my garden this year:

Chinese Yam growing up a trellis with Brazilian Spinach and Mushroom Plant growing underneath