Keeping Ponds from Freezing

Q. I have a small garden pond with hardy waterlilies, some grasses and fish. How do I keep the pond from freezing this winter?

A. Cover the pond with a sheet of plywood, and insulate it with an additional layer of leaves or straw. A small commercial pond heater will also help keep the pond from freezing solid. If the water surface freezes, pour boiling water over the ice to create a hole for aeration. Although hardy lilies can withstand the cold, they will die if their tubers freeze, so it is a good idea to monitor your pond constantly during extremely cold weather.