You should really feed them all year. Most fish will feed small amounts when the water temp is above 6 degrees c.

I always feed my fish throughout the winter on milder days...it keeps them ticking over during the times when it's too cold to feed and they rely on their body fat to live on.

Hi, I feed mine as well when its milder, they tend to mooch about more looking for food .

You should only feed wheatgerm pellets in the winter, fish need warmth to digest food and if it goes cold their gut slows down causing problems.
We have two ponds, the big one has goldfish that regularly replenish the stocks the heron takes and nearer the house is the koi pond, the ghost koi are quite big now and last summer we bought some pretty koi
That was when it was explained in detail about cold weather feeding. We wait until they actively look for food then feed wheatgerm, changing to floating sticks in summer months. His other advice was to feed fresh food, doesn't have to be expensive just from somewhere that has a good turnover of stock, especially if buying it loose.
It was a koi supplier near to Nottingham, very knowledgeable man.

Thanks Folks for the advice, off to buy some wheatgerm for them soon :o))

I have gold fish and I dont feed them in the winter and restart when the weather starts to change in spring as the fish become active.

Drc, that is the way I have been doing it over the years, still not sure when to start feeding them again though, its still cold here, so I suppose it would be best when it warms up more, what are your thought on that? :o))
Jenfren say when its warmer too. :o))

I agree with when its warmer, they don't need it as their metabolism slows down in the cold, as the water warms they become more active, we don't feed immediatly but wait until they are swimming around at the top, the goldfish and the koi recognise us and wait to be fed
If you are not sure drop a couple of pellets near them, if they dash to eat it add a little more, if they ignore it then remove the food with your net and try in another few days if its still warm
Rarely before end of march/april its all down to water temperature

You have all been so helpful, Thanks for all your input.
xx Jackie xx