Hi. I have a European elm. I need to make a branch thread grafting. This year I will growing a donor branch. Do I have to be thread grafted only in the next spring, or can I do it in the middle of summer, when the donor branch is lignified and reaches the required length? Is it necessary to remove all the branch leaves, or only in the place where I pass through the hole?
The donor branch might need to be lignified - I haven’t tried using branches that grew the same year.
That said, you can graft in the middle of the season (May/June/July) if you defoliate the branch first.
Will full defoliation weaken the branch? Or can I partially defoliate the branch tip, leaving the leaves at the base?
Defoliating does weaken the branch, but if the branch is strong enough, it will be OK. If you keep the inner leaves the tree may not want to invest in the growth you want to keep past the graft point.