When I cut part of a branch to get cuttings during the winter, sometimes (often enough) the branch remaining on the trunk dies up to the trunk even if the remaining branch has 2 or 3 more nodes still left. I notice it only during the spring that the pith has dried up too. I keep the pruner clean. I can't figure it out why it happens. The soil never dries during the storage. I don't have record if this happens to the plants stored in basement cellar (40~45F) or those stored in the attached garage (24~34F).
Has anyone else observed this problem and how to avoid it ?. I hate it when the branches die on a plant trunk.
This year I may use grafting wax on the cut after taking cuttings to test if drying up of the branch can be avoided.