When trimming a rose, the gardener typically cuts through the petiole, which attaches the leaf blade to the stem. Trimming can involve removing the entire leaf or just parts of the leaf blade, depending on the purpose of the pruning.
When a gardener trims leaves off the stem of a rose, they are typically cutting through the petiole, which connects the leaf blade to the stem. The leaf itself consists of several parts including the leaf blade (the broad, flat part commonly recognized as the leaf), the petiole, and sometimes leaf stipules at the base of the petiole.
If the trim is meant to remove the entire leaf, then the cut would be made where the petiole meets the stem. However, if the trimming is partial to shape or manage the growth of the plant, then various parts of the leaf blade might be cut without removing the entire leaf.
Pruning is an essential part of plant care, as it helps to encourage healthy growth and flowering. For roses, it can also help to maintain the shape of the bush and facilitate better air circulation, which reduces the likelihood of plant diseases.