My uncle's pond in NJ has that lousy red clay soil (Actually fantastic for holding water) and we find it tough to get plants growing. I have tried many times and am finally successful to some degree. Compounding that, there are pesky geese that show up and eat everything. For the plants around the edge like iris, we dug large holes and planted the plants with topsoil around them to get them going and used some fertilizer spikes in there. For the geese, we made small fences around the plants with fishing line to keep them out.
