Not convinced: it lacks the hardiness of each plant

The book is nice but the selection is fairly standard I think. In fact it starts from the principle: all the selected plants are rustic beyond -10 ° C. How much? You will not know, because the author does not specify the hardiness of each plant. For me it is a huge mistake, there are regions of France where one can have -20 ° C cold winter peak. Regarding the selection, a lot of Asian plants, not enough for my taste ocean plants (they can be counted on the fingers of one hand), yet there are Australian or New Zealand plants that resist beyond - 10 ° C (perennials or shrubs) and now we can find in nurseries.