Where in Sweden are you? I have family in Orsa and Mora and my mom just took
over my great aunts property (she died recently at 99.5 years old) which
contains a huge garden that grew a large variety of vegetables. I can ask her if
she ever tried to grow yams or had some growing but I don't ever recall seeing a
yam in any part ofScandinavia.

Yams/sweet potatoes are sweeter than squash. There are different varieties.
The Japanese white sweet potato might fare better in colder climates.

Elainie