Rhubarb leaves become very nice bird bath and stepping stones. In order to cast a bird bath, you need a large rhubarb leaf and a small or a piece of a leaf, sand and concrete. It is good to have a tarpaulin or similar to be on when casting.
Pour up a small pile of sand, it is good if the sand is damp. Shape the pile as a low hill with flat sides. I cut away the stem and carve so it will be as flat as possible where the stem was. Lay the leaf up side down on the sand. Take the small piece of leaf and place it under the big leaf where the stem was, this is just because the leaf is heart shaped. This will prevent that the bird bath will leak.
Mix the concrete and pat it over the leaf so that it becomes thinner towards the edges and thicker in the middle. Try to stay inside the leaf edge, it will look better that way. When finished, put a plastic sheet over it and let rest for two days before you turn the bath.
Then you can gently start peeling away the leaf. You will probably not get rid of all leaf residue at once. It’s better to let it be fore some days so the leaf will dry. Then you can brush and scrub off the residue.