The requirement emerges

Over the years I had imported various fruit trees. A Victoria plum, simply because I think they’re the finest plum there is (although, apparently, not quite as hardy as I imagined initally). Another Victoria because the first clearly wasn’t happy. A Concorde pear because I think they’re great as well. An Abat Fretel, a local pear. A mulberry and a couple of cherries.
This should all have worked but owning another house in a different climate is always a learning experience. The approach to laying patios is different, so also are plumbing joints, both because of the -15C we often experience in winter. Blue sky and very little snow but it can get very cold and stay that way. The local record is, I think, -29C sometime in the late 70s.
Termites are new to Brit arrivals and there is no Silverleaf (but there is Colorado beetle) so the plums can be pruned anytime after flowering.
Gradually as I began to understand this type of issue better it dawned on me that the orchard simply was not viable without quite a lot of help. Yes, it does get lots of sun. But the water in the Dordogne generally is pretty hard and the terrain is frequently a not very friendly combination of chalk and clay. And the rainfall between Easter and October can be pretty light. And when I tested the soil it was pretty much nutrient free.
So quite alkaline soil (sort of 8.5ph and pears hate it), no nutrients and no water.