I just observe the nature in and around my pond, but eating vegan I occasional cut off the bottom stem of cattails, peel it down to the inner white portion and add that to salads. My experiment with the foam island showed me that not only flowers but also spinach mustered and probably many other vegetables can most likely be grown. You see at the ends of the island the spinach mustard is still going strong even though the flowers are done. No weeding or watering, just plant and forget.
Even when the flowers were beautiful you can see the spinach mustered was doing well.
