The air is turning crisp across most of the US, and you’re not the only one who feels it: If you’re a pond owner, your fish and plants are starting to notice the change in temperature, too – and they need your help getting through the long, cold winter to come.

Skimming pond

Using a net, remove all debris and fallen leaves from the water surface, the pond bottom and around the sides.

Photo Credit: Courtesy of TetraPond

Cover pond with net

Leaf netting over the pond will help keep falling leaves and other debris from collecting in the water.

Photo Credit: Courtesy of TetraPond

Seasonal feeding cycle

Feed your pond fish based on water temperature.

Photo Credit: Courtesy of TetraPond

Frozen pond
Deicer illustration

Deicers are designed to keep a small area of a pond ice-free during winter, allowing gases that can be toxic to fish to escape.

Photo Credit: Courtesy of TetraPond

There are many steps to winterizing a water garden. By taking the time to do the proper seasonal groundwork in fall and winter, you can ensure you’ll have a beautiful, healthy ecosystem come spring. Here are the steps you should consider when closing your pond for the season:

Prep your pond and plants. As warm temperatures continue to decline, it’s important to prepare your water garden for colder times ahead – and it all starts with a clean pond. The best time to clean a pond is before temps dip below 50 degrees F. (Fish are still active then, and they won’t sustain injury during cleaning.) Using a net, remove all debris and fallen leaves from the water surface, the pond bottom and around the sides. If you have a lot of falling leaves, use leaf netting over the pond to avoid further debris from collecting in the water.

Next, protect your pond plants from the elements. Prune dead stems and leaves from them to prevent decaying during winter. In late fall, remove your nonhardy aquatic plants – like water hyacinths or tropical lilies – from the water. Store these beauties in warm, frost-free conditions indoors until next year.

Move your marginal plants that are growing in baskets and around the perimeter of the pond to deeper water to prevent them from freezing in pond ice. Hardy water lilies can be left in the deep end of the pond over winter. In very cold areas, bog plants should be insulated with straw or a commercial insulation material.

Shut it down. Once your pond is clean and your plants have been cared for and/or removed, it may be time to shut down your pond equipment – namely the pump, filter and UV clarifier. If you live in an area where winters are warm or moderate, you can continue to run your pump to keep the pond surface from freezing.

If you live further north, where cold temperatures are more extreme, you should shut everything down for two reasons: First, a running pump will mix colder surface water with the slightly warmer water at the bottom of the pond, where fish take comfort and hibernate for the winter. Second, you risk the chance of diverting water out of the pond and emptying it when flowing water begins to form ice – especially on features like waterfalls or streams.

Invest in a deicer. If you haven’t already invested in a deicer for your pond, consider purchasing one (and installing it) before it gets too cold – especially if you have fish. (In small ponds, a deicer is also helpful in preventing ponds from freezing solid.) Deicers are designed to keep a small area of a pond ice-free during winter, allowing harmful gases to escape. These gases, which are produced by decomposing organic material, are toxic to fish when they’re trapped beneath the ice that’s covering the pond’s surface. Keeping an ice-free opening at the water’s surface will help your fish breathe, maintaining their health and longevity.

As with people, winter can be stressful on a fish’s immune system. Deicers also alleviate stress during the winter, making it easier for your fish to withstand diseases that are more prevalent in the spring.

Change the feeding cycle. Unfortunately, there seems to be quite a bit of misunderstanding among pond owners as to the winter practices that keep our pond pets healthy and able to withstand the harsh winter months. As air temperatures begin to drop, so do water temps. In most parts of North America, water temperatures start to dip in September/October. To help your fish accommodate to this temperature change, you need to start changing their diets.

At TetraPond, we recommend a “seasonal feeding cycle.” When water temps are between 39-50 degrees F, we suggest you put your fish on a wheat germ-based diet. Wheat germ is ideal to transition fish in (and out) of winter because it’s highly digestible at low temperatures. This is especially important because in the colder months, fish metabolism and the pond’s ammonia-reducing biological activity are greatly diminished. The next step in seasonal feeding is to stop feeding fish when the water temperatures are 39 degrees F or below.

Remember, your plants and fish don’t enjoy freezing anymore than you do. Take the time to follow these important steps when preparing your water garden for winter – then enjoy a healthy, happy and beautiful pond come spring!