I was just thinning out the watercress in the waterfall and bog and thought I would share this picture: I planted the watercress about a month ago and have already "harvested" several buckets full. This is a shot of the impressive root system that this plant produces in a very short period of time and demonstrates why it is such a great filtering plant for your streams, waterfalls and bogs. It grows really fast so you do have to watch it to make sure it's not diverting water. But it's easy to pull out and your fish (or compost pile or juicer or salad or... ) will love it! And it's cheap if you can find it in your produce department - I buy a one dollar bundle every year and end up growing bushels of watercress with zero effort.