Make cement cloth planters. Approximately a water/cement ratio. Add drainage holes in the planter before it completely hardens to prevent cracking. You may also want to apply a couple coats of cement sealer after the planter is dry.
DIY Concrete Leaf Bird Bath DIY Concrete Leaf Bird Bath - love this idea! Those leaves look like rhubarb leaves to me. Hmmm may have to do something like this. Especially if I do a cob house some day, this would be a great wall feature/shelf.