In the 1700s, grapes were produced in Grenoble, or the Rhône-Alpes region, but a plant disease made them difficult to grow. Farmers switched to growing walnuts, or noixin French, because they grew well in the climate.
Walnuts grow well in this area for two reasons. First, Grenoble is surrounded by mountains which make winters here long and cold. Bugs that would eat the walnuts cannot survive the long winters. Second, the large Isère river in the city provides lots of freshwater that is rich in nutrients for the trees to grow.
The walnut trees in Grenoble are not a threatened species. Walnut farms can be found all over the region and are very important to the local economy. Grenoble walnuts are protected under French law that regulates its production to make sure they maintain their quality standards.