Small Holes in Rose Canes? Likely Leafcutter or Carpenter Bees

Tiny holes at the tops of freshly pruned rose canes that lead to dieback are usually the work of leafcutter bees or small carpenter bees—not a pruning mistake. These solitary bees bore into the soft pith to lay eggs. Rose twig girdlers can also cause damage, but they girdle the stem in a spiral pattern under the bark.

Since both bees are valuable pollinators, chemical control isn't recommended. Instead, seal pruning cuts with Elmer's glue, petroleum jelly, or a thumbtack pushed into the stub to deter future nesting.