I’m just passing the mountain village Otta in Gudbrandsdalen on the train . In 2009, I visited several old farms in this area to witness first-hand the old onion turf roofs still to be found nearby and collect some samples (see http://www.edimentals.com/blog/?p=14436). Norway’s old edible roof gardens are also described in my book Around the World I 80 plants! I recently heard that a botanist, Bjørn Harald Larsen, did a thorough field study of the area last year (2016) and made a number of new finds. His report can be downloaded below (with many new pictures!). Bjørn Harald has tried to partition his finds of old Allium fistulosum (pipeløk / Welsh onion) in this area as follows: There are now 10 intact roof locations documented of 31 «original known onion roofs»; 12 intact of 16 finds where plants had been moved / planted from older roofs; 2 occurrences where plants have naturalised on dry slopes; a few that have been planted in gardens; and finally two instances where plants seem to originate from other cultivated forms (i.e., plants have a different growth form – I had also noted this when growing out some of these onions in Malvik).