We got to be a bit addicted to watching the sedum grow while we had the luxury of scaffold to view it from. If you enlarge this shot you can see the droplets of water on the sedum, which get adsorbed into the pods on the ends of some of the varients and are used as a reserve for the plant and give it better resistance to drought. Indeed, over watering can encourage weeds and grasses that need more water than the sedum to survive.