Do I remove all last year's old flowering bracts or do flowers form from these?
Certified GKH Gardening Expert
Any literature on pruning oleanders I have read does not mention removing the flowering bracts. When pruning an oleander the focus is usually on the limbs, which you prune if they are dead or damaged or do not fit into the shape of the shrub you are trying to maintain.
Specific guidelines on how to prune oleanders can be found here: