Flowered Leaves is a Better Than Adventure! mod that allows you to interact with a leaves block while holding a flower to attach it to the block.
Flowered leaves can be interacted with an empty hand or broken to return the flower.
<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/RoMepHvWI8Y" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>