Tending to Horsetail

I think our horsetail is dying.  Although it is a weed and it is still breeding, it is definitely getting dry and brown.  As you can see from the pic it still has many pretty green stalks, but there are just so many brown, dead ones too.  We purchased the horsetail at the very begining of summer and immediately split it up into 2 equal size containers.  It was sort of an experiment to see how quickly it could grow. It doesn't come cheap here in LA, but we love the look so much. It started multiplying almost immediately. At that time it had full sun and we watered it very little. Donny said he read that the horsetail should be watered weekly.  In just a few short months our rooftop garden has grown considerably. We now have over 25 containers up there.  To make it more pleasing to the eye, I recently moved the horsetail to a different spot. This area probably has more wind and a bit less sun.  We've also watered it a lot more. Since the move the horsetail has not responded postively. Most of what I've read online is contradictory.  Some say it needs a lot of water and sun, others say it is fine in the shade.  I am going to cut back the brown stalks and see how it responds.