All of the plants I have in the inventory / plant profiles can successfully grow in Denmark. I am up at about 60 plants now in terms of documenting the edible
trees and shrubs that work here.
The Trifoliate orange card was just an example, I have many others profiled in the downloadable PDF file.
Seed swaps, polyculture gardening info, forest gardening tutorials, bioregionalism mapping, rare germplasm sales, and more at http://biodiverseed.com