I get asked a great deal about growing Carya cultivars for nuts in the UK, Pecans mostly but also Hickories and Hicans.
We’re growing them here and others are doing the same but I understand that everyone wants to know if they will fruit regularily here. The answer I give is yes they should (ours are a few years away) and I know of a few people already getting nuts but there is no guarantee that they will grow and fruit everywhere in the UK, we have some extremes of climate.
We grow and supply trees grafted by Ton Friesen in Nunspeet, Netherlands and they fruit successfully for him when they get to 8-10 years on average, these are all grafted named cultivars, below are some picture of the nuts on his trees this October. His climate is very similar to the South Midlands in terms of temperature, although he’s often a little wetter than us surprisingly.
I would say good deep soil with decent drainage (all walnuts hate wet feet), protection in the first few years. All Carya will also spend a few years putting down deep taproots before really growing upwards but once happy will grow a meter a more a year.
The Pecans are all Northern or Ultra Northern cultivars and all the Carya he grafts are on Northern pecan rootstocks grown specially for him.
Image 1 & 2 are Hicans, the next two Pecans.