If you live in a colder climate where it snows and the ground freezes, then winterizing your pond is essential.  It is important to winterize your pond correctly to protect your fish and to salvage as much plant life as possible.  By taking the following measures in the fall, your pond will be prepared for the winter and your fish and plants should be able to last until the next year.  Here are some helpful tips to follow when winterizing your pond:

1. Pond Fish:  The climate that you live in will have an impact on how to handle your pond fish in the winter.  If you live in a climate with mild winters, then it is a good idea to install a pond heater in your pond to keep the temperature of the water comfortable for your pond fish.  A pond heater, such as the Laguna Pond Heater – 315 watt, is perfect for winter where the water freezes over.  This pond heater is designed to provide your fish with a breathing hole for air throughout the winter.  Your pond fish will be dormant in the winter, so they will only require feedings in the fall.  Use a pond fish food, such as the Spring-Autum Pond Food, in the fall and spring only.  If you live in an area with severe winters and can’t use a pond heater, then it is best to store your fish indoors in a tank for the winter. 
2. Plant Life:  Maintaining plant life during the winter is tricky, but possible.  If you have any tropical pond plants, it is best to get rid of them because they are hard to keep alive unless stored indoors in a tank.  Non-tropical plants have a good chance for survival outside when taking care of properly.  In milder climates, hardier plants may be kept in the pond.  To keep them in the pond for the winter, remove them from the pond, trim them to the stub of foliage, and return them to the deepest area of the pond with no supports.  If you decide to remove them permanently for the winter, place them in a warm indoor spot and use mulch to cover them up.
3. Drain and keep debris out of the water:  Your pond water should be drained a few inches during the fall to prepare for the winter.  It is also a great idea to make sure the water is free of leaves and other debris to prevent them from rotting in your pond during the winter.  Use a pond netting, such as the Dewitt Pond Netting, to keep leaves and branches out of the pond.  Check it on a regular basis and your clean-up will be much easier.