why are some of my roses not thriving.. the leaves are small and disfigured and yellow. some time ago i did find loads of greenfly on the roses as they were coming into leaf and sprayed accordingly.
The roses are showing classic symptoms of weedkiller damage, probably glyphosate, due to carryovwer in the sprayer. These are probably the ones sprayed first.
They normally grow out but it can take two years. Do not prune.
It is always wise to have two sprayers, one for weedkillers and one for any thing else.