Winter Maintenance for your Garden Pond: Tips and Advice

winter pond careAs the winter approaches you need to think about preparing your pond for the winter months.

With autumn now coming to an end your pond will start undergoing a significant change.

With temperatures dropping your fish will start to hibernate, their activity and metabolism will reduce significantly.

At this time of year there is a strong rick of ice freezing the surface of the pond so if you have pond plants and pumps a bit of maintenance and cleaning will be required.

Winter pond care is essential for the health of your pond, doing these vital preparations before winter hits will help your pond survive the rigorous weather and give it the best possible chance of getting of to a good start when the weather starts to warm up in the spring.


Should I clean my pond for winter?

Cleaning your pond should be completed before the water temperature falls below 10°C as any fish you have will be active and less likely to be hurt as you clean.

Start by scooping out any fallen leaves on the surface with a net before taking the sludge and organic debris at the bottom of your pond.

To clean the sludge you can use a a long handled net that can reach to the bottom of your pond, a pond vacuum and a sludge treatment.

If the debris is left on the bottom of your pond you will have a bigger mess to clean up when spring arrives.

At this point you could add cold water bacteria to the water, this breaks down fish waste and organic debris during the winter months keeping the water cleaner and clearer whilst helping to reduce toxic gas building up.

It also helps with spring maintenance by digesting the debris which would normally accumulate in the pond during the winter months.


Is it a good idea to cover my pond at winter time?

During autumn it’s a good idea to use a pond net to catch the falling leaves which will make winter maintenance a bit easier.

For winter a net is useful for protecting your pond from predators which look at pond fish as easy targets due to the lack of vegetation leaving the pond exposed.


Do I need to remove my pond pump during winter months?

It is not essential to remove your pond pump for the winter, in fact if you have fish it’s better to leave your pump running.

If you don’t have fish or livestock and use it as an ornamental pond then there is no need to leave equipment running throughout the winter.

If you are leaving your pump running in the winter months you might want to consider decreasing the flow rate of your pump by about 50% and raising it up from the bottom of the pond placing it on a shelf or bricks.

This will help avoid the re-circulating of the warm water at the bottom of the pond where your fish languish with the much colder water at the ponds surface.

Having a pump running throughout the winter also help to keep a small area of your pond from freezing over, the warmer water from below the surface gets re-circulated, warming and agitating the surface water keeping ice at bay and allowing noxious or toxic gases to escape.


Should I remove my pond filter during the winter?

There are 2 different thought about removing pond filters for the winter. Some say to remove them to stop them getting damaged in the harsh winter months others say that leaving your filter in for the winter helps keep the bacteria that has already built up in the filter alive.

Although in the winter months the bacteria will not be active they will survive with the oxygenated water from your pump, come the warmer weather the bacteria will reactivate and get back to work.


What happens if my pond freezes over?

If your pond freezes over for prolonged periods of time the natural gasses that form in your pond cannot be released, instead they get trapped under the iced over surface while the opposite happens of not letting oxygen enter your pond which is vital for your fish to survive.

If you check your pond and find it is frozen over the one thing you must not do is try and break the ice.

If you try to break the surface ice all you will do is send shock waves through the water causing stress to your fish and could even kill them.

You should never pour hot water over the ice as this will cause extreme temperature changes which will also affect your fish.

If your pond has frozen over one way to melt the ice is to lay a small hot water bottle with warm water on the surface allowing to the ice to melt slowly without heating the water too much.

Don’t lay the hot water bottle on the surface and walk away, you need to stop it falling through the ice once its melted.

If you don’t have a water bottle a pan with hot water can be held on the surface until the ice melts.

They say floating something on the surface like a ball does help stop ice forming as its gentle movement breaks up ice as it forms but I think this is an old wives tale as its more than likely going to freeze in place. A better option is to use a de-icer or pond heater.


Do I need to use a pond heater in winter?

A pond heater is a great way to ensure there is a small section of pond that doesn’t freeze over but although they are not an essential it is something that we would recommend if you pond succumbs to freezing conditions on a regular basis.


Should I change what I feed my fish in the winter?

Fish are cold-blooded animals so as their surroundings change so does their body temperature and their behaviour corresponds to how hot or cold they are, as the colder weather begins to take hold their feeding pattern changes.

In autumn your fish will be happy feeding on a high protein diet but at the same time will be building up fat reserves to see them through the colder winter months when they can no longer digest protein rich foods.

As temperatures drop during the winter months your fish will  adapt and start to slow down their metabolism and eventually go into a semi hibernation state.

During this period you should stop feeding your fish a high protein diet as it might remain undigested in the stomach of the fish causing them bloating and constipation.

As winter starts to hit you should reduce the amount of food you feed your fish to about 2 to 3 times a week, any more could result in uneaten food impacting the water quality.

Fish can take up to 3 days to digest their food in the winter months.

If the temperatures drop below 10°C you should not only reduce the amount of food that your fish are feed but consider changing their food to a wheatgerm based food available in pellet or stick form as they contain less protein for the fish to digest.

There are specialized foods that you can feed your fish as their dietary needs change through the winter months which are designed to stop fish having undigested food rotting away in their stomachs and reduce the amount of ammonia being excreted into your pond.

At around 5°C your fish will naturally stop eating and enter into a state of semi hibernation at this point they will retreat to deeper areas of the pond where the water is warmer.


Is there anything I should do to protect my pond plants in winter?

There are a few things to do to protect your pond from pond plants but on the whole pond plants are very hardy.

Most pond plants will rest during the winter months and will start to loose their leaves as they stop growing.

Any leaves that have been shredded should be removed from your pond before they sink to the bottom and decompose.

If you have non hardy plants such as water hyacinths in your pond we would recommend removing them indoors to avoid frost damage.

Hardy plants can be moved into deeper parts of your pond to prevent their roots freezing.

As your plants die back in the autumn you should prune back dead leaves and stems to prevent them decaying in the water over winter.

You can cut hardy plants such as waterlilies just above the base of the plant, any marginal plants can also be cut back if there is a risk that they could droop over into the water.


Do I need to protect my pond from Herons?

Winter is a time when your pond would be more prone to heron attacks because the plants that once protected your fish throughout the year are no longer there, but during winter your fish will be hibernating at the deepest part of your pond away from herons.

A net over your pond not only stops leaves and debris from falling into it but also protects you fish from predators such as herons.

You can also use a decoy to keep the herons away.