Meanings of prune a rosebush in English

The only sound was the hummed melody of an aged gardener, bending over to prune a rosebush.

He was kneeling on the grass, pruning a rosebush, but shot up with a youthful spring to his legs and yelled, Hey!

She was in her garden, pruning a rosebush with the single-minded concentration people devote to simple physical tasks to distract themselves from emotional turmoil.