Early preparation for cold weather means a more enjoyable garden even during the off-season. A pond in a highly visible location needs to look good during the winter even when the plants have no leaves. Furthermore, a clean pond in winter will mean healthy happy fish.

With cold weather approaching, fish become ravenous, perhaps sensing that a long winter without food is coming soon. Goldfish and koi will consume as much as twice their normal amount of fish food once the water temperatures start to drop. Be careful not to overfeed, but be aware that fish will want to eat a lot more for about six weeks. Feed with wheat-germ fish food when water temperatures drop below 50 degrees and discontinue feeding at 40 degrees. Once the feeding frenzy subsides, the fish will lose interest in fish food altogether. Heavy feeding will change to total disinterest overnight. Once the fish have decided to stop feeding, put away the food until spring. On a warm winter's day your fish may act hungry, and you may give them a snack if you choose, but it is not really necessary to feed them at this time.

STOP FEEDING FISH DURING LATE FALL WHEN WATER TEMPERATURES GO BELOW 40 DEGREES!

Keeping the pond clean can be as simple as occasional removal of leaves from the pond's surface. Once the leaves sink to bottom of the water garden they are more difficult to retrieve. Lying on the bottom of the pond, the leaves begin to decompose and break up. Rotting leaves use oxygen as they break down, which can lead to disaster if the pond freezes over, sealing out a fresh supply of oxygen. Get the leaves early to avoid later trouble. Besides, getting the leaves off of the surface is more pleasant than putting your hands into the cold autumn waters.

Falling leaves are easily removed as they drop from the trees if a pond has a skimmer system installed. This ingenious component constantly vacuums the pond surface; trapping leaves inside a net as soon they land on the water surface. Throughout the entire season the skimmer cleans the floating debris, but does the best work during the fall when the winds bring in the most leaves. During this time, more frequent cleaning of the pond skimmer is necessary to keep up with leaves that are drawn into it.

Water gardeners often cover their ponds with fine mesh netting to catch leaves before they settle to the bottom of the water. Thin black plastic mesh is hardly noticeable when it is stretched tightly over the water garden. Some gardeners leave the netting on throughout the winter, while others remove it as soon as leaves are finished falling. Early removal may appeal more for aesthetic reasons, but if leaves hang on the trees (like Oak leaves), or if your neighbor neglects to rake, consider leaving the netting in place longer. While most netting is supposedly made of floating material, it is preferable to stretch the netting taut to lift the material off of the water. This keeps the leaves dry so they are easier to remove. Some gardeners have found that removing the leaves from a net with a leaf blower is effective while the leaves are dry. Hold the net tightly by staking with plastic camping stakes or by holding down the edge of the net with the rocks surrounding the pond.

Cleaning the water garden may be necessary once the build-up of debris in the bottom of the pond becomes excessive. An inch or less of silt is manageable and does not necessarily need to be cleaned. More material on the bottom means the possibility of oxygen depletion when the surface is frozen. More than an inch on the bottom necessitates cleaning of the pond entirely or at least the removal of the silt layer by vacuuming or siphoning. A pond vacuum tool helps to remove the coarser debris, but not the fine stuff. The finer material passes through the vacuum and goes back into the water during the vacuuming process. A Pond Vac operates off of the water pressure of your garden hose. The pressure must be sufficient to cause the suction through the vacuum head. (Remember: Always dechlorinate water that is being added to a pond with fish.)

Leaves and stems should be pinched off as they turn yellow, indicating they are going dormant. Remove the dying leaves to prevent them from falling to the pond bottom and contributing to the debris layer. Some plants that have interesting foliage can be left during the winter for dried texture while the pond is dormant.

Care Sheet - Fall and Winter 2001 (c)

WINTER

Once the water garden has gone completely dormant, there will be no leaves left on water lilies or most other plants. Underwater oxygenator plants remain as cover for the fish during the winter. These plants are important to the fish for protection from bright sun and predators. If they are long and gangly, the oxygenator plants can be trimmed to a length of about twelve inches so they are a bit neater.

Plants in pots can usually stay where they have been all summer. Lowering them to the pond bottom is not necessary unless winter temperatures cause the pond to freeze to below the rim of the pots. Plants most sensitive to freezing are pickerel rush, Thalia, and arrowhead. These must be lowered to the bottom of the pond or covered with deep water. Water lilies should be left at their normal pond depth of 18"-42" the year round.

NEVER FERTILIZE PLANTS IN THE WINTER!
NO FERTILIZER SHOULD BE APPLIED BETWEEN SEPTEMBER AND MARCH.

DO NOT FEED FISH DURING THE WINTER OR AT ANY TIME THE WATER TEMPERATURE IS BELOW 40 DEGREES! THIS IS USUALLY MID-OCTOBER UNTIL MID-MARCH.

To prevent the pond from freezing over completely, keep the water moving by operating the pump throughout the winter. Disconnect statuary or fountain nozzles and direct the water flow from the pump straight up towards the surface. The miniature geyser effect keeps the undulating surface from freezing even during extreme low temperatures. Operate the waterfall during the winter and enjoy the beautiful ice formations that form where water splashes and builds up. Hopefully low-voltage lighting is installed in and around the pond illuminating the ice, for a stunning lighted winter ice sculpture. Be careful to keep an eye on the ice to prevent excessive build-up that may divert the flow of water out of the waterfall or stream. Break out ice dams if they seem to be obstructing the flow. If electrical power is interrupted during freezing weather, you will have to wait until the tubing thaws to turn the system back on.

In place of moving the water to prevent freezing, a floating de-icer can be installed to keep the surface partially ice-free. Never operate a de-icer and a pump at the same time. The cold, moving water keeps the de-icer operating all the time, using electricity while not preventing freezing. A de-icer keeps a hole in the ice, but does not necessarily prevent all ice from forming. Install the floating de-icer at the edge of the pond, not in the middle to gain advantage of reflected heat. Provide wind shelter if needed to allow the unit to operate normally and efficiently. Strong winds will cause the de-icer to freeze into the pond, even though the unit is functioning properly. The cold wind causes the thermostat to keep the heater going, but the heat is swept away by the air movement. The unit will use electricity, but will not thaw the pond surface. Improperly installed and tested de-icing units are often returned, but are found to operate normally.

If the de-icing unit freezes into the pond's surface, try this air test before declaring the de-icer dead: Take the unit out of the water and put it in the freezer for one hour to allow the thermostat to reset. Take the unit out of the freezer and plug it in. If it heats up, it is operating normally.

CAUTION - It will heat up rapidly, so do not touch the metal part! It will burn!. Re-install the heater with wind protection at the edge of the water garden.

NEVER BREAK THE ICE BY STRIKING THE POND! The percussion from hitting the ice can burst or damage the air bladder of the fish causing death. A damaged air bladder will make the fish swim sideways or upside down or may even cause death. To get through the ice, gently push through to break it. Melt through using hot water poured in a pan that is placed on the ice. However, a frozen pond is not harmful if the pond is relatively clean before it freezes over. The fish remain dormant below the ice right along with the plants, snails and frogs. Do not worry about them, they are fine. If the pond is dirty or if it has more than an inch or two of leaves when it freezes over, oxygen depletion from rotting leaves can cause harm or death to the fish. Operate the pump with the flow directed towards the surface to keep a hole in the ice if the pond is dirty, until cleaning can be done.

Once the winter is almost over, look for signs that the fish are becoming active. Feed them with wheat-germ food only in water temperatures of 40- 50 degrees. Regular fish foods must wait until water temperatures climb into the fifties before use (usually in April).

As days get longer and water gets warmer plant growth will soon begin. Start fertilizing plants about the time you first see floating water lily leaves. Lift any plants to their regular growing level that were lowered to deeper depths for the winter, as early as possible.