Thai Potatoes

The main variety of potato in Northern Thailand is Spunta which are similar to Cyprus potatoes, (I think that's how you spell it Gonzo!). They are versatile and fairly robust. The problem is that from around this time of year on they won't grow in this country because the ground becomes too wet. So they put them in cold storage and the price doubles. They are still usable but the water content increases which means they are difficult to chip. They remain that way until the new crop appears around late November. A few farmers at high elevations and especially around Doi Inthanon (near Mae Jem) have been experimenting with other varieties, but so far the experiment has not been an unqualified success and price has proved prohibitive (I'd love to get some Jersey Royals or Desirees at decent prices). We use around 80-150KG of potatoes per week at The Olde Bell, so I've tried to research the market!

Sweet potatoes, such as the OP mentions seem to be only available at certain times of year, maybe for the same reasons. I'd like to use them more but they are often unavailable. The best place to try as someone mentioned above is Talaad Meuang Mai (New City Market) which covers most of the block up river from the US Consulate building. That is the man wholesale fruit and veg market for Chiang Mai.