Each year in the early summer, staff at the island's Yuushien Garden cut thousands of peony flowers and float them in a pond, creating a dazzling display of red, pink, purple and other colors.

Water poppies spread quickly and provide shelter, good for warmer zones. Dwarf cattails filter water, grow in zones 3 to 11, and prevent erosion. Yellow flag iris brightens in spring, but remember ...

It's important to remove any rotting organic matter in the pond such as dead leaves and flowers. A form of algae known as blanketweed is often found in ponds, and if left unchecked can choke the ...