There is a tendency to think that there is nothing much to do to your outdoor pond in the winter and that you cannot spruce it up or make it look better. Your pond does not have to have a dormant, unattractive phase until the sun shines. There are things you can do to maintain it and enhance it so that it is nice to visit all year round.
Leaf netting is a pond owner’s best friend. Before the leaves fall in the autumn cover the entire pond with leaf netting. It is much easier to keep the leaves out than to remove them after they fall into the pond. Do this early and you will also save your pond from looking like a disaster area in the Spring.
Remove tropical or annual plants from the pond as they will decay and pollute the water. This will leav you looking at a mucky mess all winter and it is just not necessary. It is also not good to leave leaves in the pond with any wintering fish and if there is a lot of plant matter settling to the bottom of the pond then it can actually raise pond levels and flood your yard.
This is a good time to divide some types of aquatic plants (waterlilies and iris) and place them back in the pond. It is not necessary to wait until Spring. You can also cut back the foliage on hardy perennial plants and lower the pots they grow in to the bottom of the pond.
Your cue to start winterizing the pond is when the temperature drops to forty degress Fahrenheit. This means it is time to turn off the pump for the winter. If you have fish turn down the water flow on the pump. Keeping the water flowing through your biological filter allows the bacteria to live therefore ensuring good water quality when you increase the pump’s water flow early in the spring.
You can add a floating de-icer to keep an area free of ice. This opening is necessary during periods of ice cover to allow an exchange of gases throughout the pond that it does not become stagnant.
If you like, plant Water Hawthorns, which are a mainstay in Japanese ponds. This gorgeous plant blooms through the ice. They are an opposite growing cycle to most plants and grow and bloom fall through spring and go dormant in the summer. They help keep the water oxygenated throughout the cold winter months.