May showers are great for sedum roof growing

The recent showery weather has been great for the sedum which is settling in and growing well. The sedum roof is already changing colour as we were told it would. It seems to adsorb lots of water, it has to rain quite hard or for an hour or more before anything comes out of the temporary down pipes. It then comes out in a steady trickle over 3-4 hours. Because of this delaying and reduced flow effect this is great for reducing the problems of flash flooding, if only all big buildings had sedum roofs. We are on low lying ground so this will all help.