We would advise you not to add fish to your pond during the winter months if the water temperature in your pond drops below 15 degrees .
That’s not to say you can’t introduce fish late in the year, some say you can add fish if the temperature is above 10 degrees but thats not the full story.
Why you shouldn’t add fish to a pond in winter
When you add new fish to your pond they need to adjust to their new surroundings, the later you do this in the year the less time they have to adjust and get ready for winter.
As winter draws closer your pond fish will start to get ready for hibernation, not a full hibernation, more of a dormant period where their metabolism drops to cope with the harsh weather.
This process could take about a month to complete, they will start by building up fat stores, you will need to feed them the food they need such as wheatgerm and as the temperature drops they will feed less and less until they stop feeding all together.
If you introduce fish too late in the year they will not have enough time to get ready for winter and might not survive.
Can you transfer fish from another pond in the winter
Adding fish to your pond in winter is not a wise move unless they are coming from an outside source where they have become cold-tolerant already, even then you will need to acclimatise them to your ponds water temperature before allowing them into your pond.
Just place the bag your fish came in on the surface of your pond and leave it there for about an hour, this will allow the temperature of water inside the bag to slowly reach the temperature of your pond.
What can you do if you have fish but it’s too cold to introduce them into your pond
Most fish you buy are usually bread and kept indoors where the water temperature is above the temperature outdoors.
If you do buy fish and your pond is too cold to introduce them too all is not lost, you can keep them indoors in a temporary home until they can be released into your pond the following spring.
While they are indoors they will continue to grow, they will not hibernate so you will need to continuously feed them throughout the winter.
You will need to monitor their temporary home to make sure the water quality is suitable and also think about covering it to stop any fish jumping out.
When is the best time to add fish to a pond
If you can, the best time to introduce new fish to your pond is late spring and summer when the temperature is at its warmest, but not too hot, this gives your new fish time to mature before the winter months arrive.