If you've seen rhubarb growing in a garden, you've noticed the plant's attractive, large leaves. These same leaves can be picked and put to use as a mold for a garden fountain or birdbath. You can make the fountain basin using a simple sandcast and some rhubarb leaves. Then you'll have to put the fountain together using a water pump.
Make a large, smooth pile of sand on the ground. This needs to be big enough for the rhubarb leaf to fit on with a few extra inches of room. Your sand pile should be shaped like a half-dome when complete and should not have any bumps or rough edges. Cover the sand with plastic wrap when the dome is complete to prevent sand grains from sticking to your fountain basin.
Mix your concrete with water following the ratio on the bag. You'll want the concrete mixture to be thick but pliable, like a pudding or cake batter.
Place the leaf on the sand pile. Pad the concrete over the leaf using your fingers. Try to keep an even thickness in the center of 1/2 to 3/4 inch of concrete, tapering to 1/4 inch thick at the edges. Try not to go over the edges of the rhubarb leaf; if you do, wipe the cement away before it dries. While you wait for the rhubarb leaf to dry, you can assemble the water pump.
Assemble the water pump in your water fountain kit and attach the lower basin. You'll have to use plastic tubing to connect the pump to an electrical outlet and you'll have to make sure the pump works. The pump will draw water up and shoot it out into the upper basin, where it will fall down to the lower basin and be drawn back up via the pump. You'll be substituting the rhubarb leaf sandcast for the upper basin.
Attach the rhubarb leaf sandcast in the spot where the supper basin would go once it's finished curing. You can use an epoxy or other strong glue to position it in place. Turn on the system to make sure everything works properly, then enjoy your new concrete garden fountain.