Hi, welcome to GoY, I think the best tip I can give you, unless you have a few acres of garden, is not to bother, the English walnut grows into a very large tree, 100ft high with a spread of 50ft, if you happen to have a very large garden, let us know, and we can give you some information on growing them, Derek.

Have a look at some of the modern varieties such as Rita which do get quite big (28ft) but they come into fruit a lot quicker than the big trees. Don't forget that the walnut produces a chemical called juglone which restricts the growth of other plants that might be in competition with it.

We have some young ones and by comparison to other trees seem quite slow growing......but i agree trees need room to grow to be seen at their best