Is there an easy way to grow watercress at home

I cant answer but I can tell you that I tried. I seemed to do ok in boggy soil (apor with no drainage holes) in a reasonably shady place. Once I thought to try it in standing water, it wasnt too happy.

Watercress is dead easy and we grew lots some years ago. Just plant in a big pot standing in a tray which you keep filled up with water. Cuttings from watercress you buy in a supermarket do really well.
You won't get the same rampant plants as growing in pure chalk springs but you will still get lots of leaves which are good to eat fresh or to make the wonderful watercress soup!
We grow it now in a spring near the house but although it works well in the spring and autumn, it goes up to seed in the summer.

You could also try American Landcress which makes a good, though somewhat sharper, substitute.