Iris are the main group of plants flowering in and around the pond in June.
Iris versicolor, Iris louisiana and Iris pseudacorus all grow with their roots and crowns covered by water in the pond or container pond (but pseudacorus Iris are usually too large for a container as they can reach 4ft tall.)
Their colours vary from white, yellow, blue, purple to black to give a bright show from late May to July.
Iris leaves in the pond will also act as routes to climb up by any damsel or dragonfly larvae when they are ready to emerge from the water.
Iris ensata will handle a very damp soil in summer but not in Winter so need to grow in a bog garden where you are in control of the water input. They will not survive in the pond itself.
Iris sibirica prefer less damp situations still so grow in a moist planting area with very controlled moist water levels. Both create part of the emergence zone of habitat growth to protect the young wildlife on its journey out of the pond.