james writes:
I have an espaliered nectarine.
It is a simple shape consisting of a single vertical trunk and a series
of horisonlat branches.

Last year I lost a couple of the branches due to a hail storm.

I was hoping that this spring I would see new shoots come from the base
of the original (damaged) branches.
This has not been the case and would like to either graft some new
growth to the trunk with the aim to replace the branch, or if there is
some other way to stimulate new shoots I would be happy to do that.

You're right, they don't grow new shoots at the base of a broken limb.
I recall a grafting technique known as budding, where you remove a bud +
surrounding live bark from a donor and slip it into a slit in the bark
of your tree. Eventually it grows out to form a branch. It's probably
something you'd do around late winter. Try a web search to see whether
you think you could manage this. There are plenty of sites with details.
--
John Savage (my news address is not valid for email)