As winter arrives in cold-winter climates, your water feature requires protection from cold temperatures and ice. Hardy, dormant aquatic plants should remain in the feature, while tropicals should be removed to a warm, indoor location. Protect your pond’s liner from ice and freezing damage to the pump, pipes or filters. A natural exchange of air is essential to maintain water quality. Before the first frost hits, follow these steps:
Winter is a dormant time for most aquatic plants in those areas that experience freezing temperatures. Hardy perennial aquatic plants winter best inside the pond if an air hole remains open to freshen the water.
Photo Credit: ©2001 Dolezal Publishing/Donna Krischan
Floating rigid-plastic foam insulation along the margins of a water feature helps prevent ice from damaging the pond liner, as well as help keep the temperature of water in the pond high enough to prevent freezing.
Photo Credit: ©2001 Dolezal Publishing/John M. Rickard
- Clean your garden pond. Remove any debris from the water and protect your plants. Remove your non-hardy species and keep them protected indoors. Hardy marginals growing in containers can be relocated to deeper water so they won’t freeze.
- Before ice begins to form on the surface, install a small heater or auxiliary submersible pump near the surface of the water to prevent your pond from freezing and to allow ample oxygen to enter the water. (Most outdoor fish species will congregate around the heater and open water areas. Dissolved oxygen supplies are most plentiful in the open water area, and the circulating water carries oxygen to all the feature’s areas and its plants.) Another alternative is to install an air bubbler similar to those used in aquariums; the bubbles of air rise, keeping the water in motion and stopping ice from forming above the bubbler.
- Leave submersible pumps operating in the feature. Moving water resists ice formation. If you don’t have a submersible pump, install a small one. Turn off and drain aboveground pumps and lines, and protect aboveground recirculating lines from freezing by wrapping them with heat-tape or insulation. If you plan to store your pump indoors over winter, keep it in a bucket of cool water so that its internal works and gaskets remain soft and supple.
- If cold temperatures become extreme, it’s sometimes necessary to add plastic foam float blocks to flex against ice expansion that otherwise could damage the liner. If you use such blocks, leave at least 20 percent of your pond surface open.
Taking the proper care measures before winter hits not only helps protect your pond during the cold dormant season, it will help make your job easier come spring.