When the leaves start falling and the air turns crisp, it’s time to prepare your outdoor water feature for winter. A few steps this fall will save you time and money next spring.
Combating Leaf Fall
Continue to keep the pond free of leaves and plant debris. Loose vegetation left in the pond will break down over the winter causing a spike in harmful ammonia levels. To help with this cover your pond with netting before the leaves start falling and keep the area around the pond raked.
What to Do with the Waterworks
Shut down any above-ground water sources such as fountains or waterfalls for the winter.
Remove the pump from the pond and store it away for winter. You don’t want the pump to run during the winter because the moving water mixes up thermal layers, making the water near the bottom colder (where fish will be). Give the pump a once-over and remove debris and clean the impellor. Internal filters should be removed and cleaned as well. Clean all filter media before storing for the winter so it’s ready to go in the spring.
When To Stop Feeding The Fish
If you have fish in your pond, you can stop feeding them once the water temperature stays below 50° F. At this temperature fish will go into hibernation and stop eating. Set up a good thermometer to monitor the water temperature. I use one with an easy viewing window with large temperature indications for quick readings.
Rather than going cold turkey, wean your fish off food as the temperatures go down. When the water temperature is steadily between 55-60° F, only feed the fish wheat germ-based foods once a day. Reduce feeding to once a week when the water temperatures stay between 50-55° F. If the temperature stays below 50° F, you can stop feeding them until the weather warms in spring. Discard any remaining fish food since the nutrients in any open packages will dissipate over time. If your area experiences a warm spell the fish come to the surface be sure not feed them, they may be coming up for air and any food they eat will not be digested.
Finally, consider installing a floating de-icer to keep your pond surface clear of ice. In colder climate zones an air hole needs to be kept open to allow for a proper oxygen/carbon dioxide gas exchange for fish to survive the winter. If your pond completely freezes, you risk losing your fish.
Preparing Pond Plants For Winter
As cold weather approaches, trim hardy lotus and lilies and then put them in the deepest part of the pond. Other hardy plants such as grasses, cattails, and iris do not need to be trimmed back in temperate zone gardens, but for colder climates just put them at the bottom of the pond for the fish to hunker down in.
You can also remove and/or compost tropical oxygenators and floating plants like water lettuce and water hyacinths. If you have space, you can bring your plants inside. Some of the ones that are a little more fragile in my zone 7 pond I like to put into plastic tubs and overwinter indoors. I make certain that I provide them with light, keep them damp and check on them weekly.