Winter and Fall FAQ

The Most Asked Questions About Fall and Winter Pond Prep

What time of year should I give my pond a good cleaning and what are the basic steps?

Late fall, while you prepare your garden for winter, or early Spring are the best times for cleanings. Drain your pond with a pump placed in the deepestt area of the pond. Place your fish in a separate container of pond water, remove all plants and clean out any debris that has collected at the bottom of your water garden. Refill your pond with fresh water and return all plants. Before adding your fish back, give them a chance to adjust to any change in water temperature and treat the water to remove any chlorine or other harmful additives.

If your pond is stone-lined, clear a location of gravel in the deepest area of your pond to place your pump. Using a regular garden hose with a jet spray attachment, wash any collected sediment down between the rocks to the low area where your pump can pump it out. Collect and discard any leaves, stems, twigs etc. that may have collected on top of the stone. There should be no need to remove/replace any stone during the cleaning process. If your pond is relatively clean and the water has been clear most of the season, it is not necessary to completely drain the pond to clean it. Rather, simply drain about 75% of the water (pumping from the bottom as you stir your water up a little to pull out any accumulated debris.

How do I take care of my plants in the winter?

Most hardy plants can be trimmed to about 3-6” after November 1st and placed in the deep section of the water garden. Aquatic grasses, reeds, cattails, rushes and similar grass-like plants should be only trimmed back to about 18 ” and placed in shallow water so that their stems rise above the surface of the water. These plants “breathe” through their stems in the winter. Water iris should not be moved to deep water since they can suffocate in water more than a few inches above the pot.

How do I take care of my fish in the winter?

There are several options for “winterizing” your fish. As mentioned earlier all feeding of the fish should stop after the water temp falls below 43-50 degrees- usually about late October. Your fish require access to fresh air during long periods of ice cover in the winter. One way to accomplish this is simply do nothing! Just let your waterfall continue to run as it has all season and the moving water will not freeze and will provide the needed air exchange. Even in severe cold, ice will form over the moving water, but the flow will not stop. The main concern would be a temporary power outage that might allow water to freeze in the line; blocking the water flow even when power resumes.

What are some good basic steps to get my pond ready for winter?

1. Reduce the number of leaves falling into the pond or remove them with a net.
2. Do a Fall pond cleaning.
3. Cut back dead or dying aquatic plant foliage during the fall.
4. Switch to a wheat germ-based fish food.
5. Disconnect the pump, filter and UV clarifier before water freezes.
6. Store UV clarifier indoors for protection.
7. Store filters indoors (if manufacturer’s directions suggest).

What about falling leaves?

Falling leaves are hard on a pond. If left in the pond, they will decay and add to the ammonia load. They can also make the water too acidic. Put leaf netting over your pond during the weeks that most leaves fall into the pond. If you have a small pond, you can drape the netting over the pond and anchor it around the perimeter with rocks.

It is advisable to have some type of support in the middle to keep the netting from dipping into your pond when leaves accumulate. For larger ponds, a strong plastic coated wire, such as a dog run cable, can be strung between two trees or from posts on either end of the pond, with the netting draped over it to form a tent. If you do not use pond netting, you should scoop the leaves off the surface and the bottom with a long-handled net.

Should I keep my pump and waterfall running in the winter?

Keeping your pump running year-round depends on the severity of the winter. If you are expecting a period of cold weather that will freeze your waterfall, you should not run your pump and waterfall. It is possible for the waterfall to freeze in such a way that the water will exit and eventually drain the pond.

If you decide to run your pump throughout the winter, it is advisable to raise the pump closer to the surface. This will minimize the mixing of colder water at the pond bottom with the warmer water closer to the surface, which could adversely affect your fish. (See "Will my fish be OK in the pond over winter?") If your pond is prone to freezing in the winter, use a pond de-icer. It probably won’t be necessary to run your pump.

Will my fish be OK in the pond over winter?

In most parts of the U.S., it is fine to keep your fish in your pond, providing the depth of the pond is 18 inches or deeper. Koi, Shubunkins, and most goldfish survive winter by staying inactive at the bottom of the pond where the water remains a constant temperature of a few degrees above freezing.

Circulating the water during the winter will cause fluctuations in the water temperature and may adversely affect fish in their state of hibernation. Be sure your pond has areas that are deep enough so it does not freeze to the bottom. Generally 18 inches depth is sufficient, but ponds in extremely cold regions of the country should have areas 30 inches deep or deeper.

Use a pond de-icer to keep an area of the pond ice-free to allow toxic gases to escape. Some fish, such as fancy goldfish, should be brought indoors during the winter. Call us at 1-866-305-5459 for advice on your specific fish. Remember, do not feed your fish when water temperatures are below 42°^F.

Do I need a pond de-icer?

A pond de-icer is essential for fish survival if you live in an area where your pond freezes over. A pond de-icer will leave a small area of the pond ice-free, which will allow harmful gases that would otherwise be trapped beneath the surface, to escape the pond. Be aware that pond heaters usually have a built-in thermostat so as long as they are plugged in and in the pond, they will turn on as the temperature drops and turn off as water temperature eventually rises.

Could I leave my UV clarifier out during the winter since it is plumbed into the system?

It is better to bring your UV clarifier indoors before freezing temperatures arrive. There is no need to run the UV during the winter. Water inside the UV clarifier can freeze, expand and damage the quartz sleeve, bulb, housing or electronics.

Should I feed my fish during the winter?

Do not feed your fish when water temperatures are below 42°^F. Feed wheat-germ based foods when water temperatures are between 42°^F and 65°^F.

When do I stop feeding my fish?

Stop feeding when water temperatures fall below 42°^F. Even if your fish are not moving around or seeking food, and the water temperature rises above 39°^F during the winter months, do not feed them.

How do I take care of my Hardy plants in the winter?

Most hardy bog plants can be trimmed to about 3-6” after October 15th and placed in the deep section of the water garden. Aquatic grasses, reeds, cattails, rushes and similar grass-like plants should be only trimmed back to about 18 ” and remain in shallow water (1-6” of water above pot) so that their stems rise above the surface of the water. These plants “breathe” through their stems in the winter.

Water iris should not be moved to deep water since they can suffocate in water more than a couple inches above the pot. Oxygenators and water lilies can stay in the deep section (18-36”) of the pond they normally grow in through the summer. As long as they are below ice level (maximum ice depth is 8-10” in Ohio), they should over-winter fine. Trim all remaining leaves and stems off your lilies after the first couple freezes to prevent them from fouling the water as they are shed.