I had the same problem in my last garden. I just gave up in the end.
I use seed, fat balls and nuts here now but note that at different times of the year, the birds have different preferences.
I love the birds in my garden. They give me so much pleasure.
Do you fill the feeder up to the top? I had the same problem, with the lot going mouldy. I decided to give the birds one more go with the nuts but only half filled the feeder. For some reason they ate the lot. Now I don't ever fill it to the top
Panda's right. Just put a small amount in your feeder and top up when necessary. If you get squirrels they can scoff them, but sometimes birds leave them alone in favour of suet treats tasty mixes in seed feeders.
Last year (or maybe the year before) Pnuts were much more popular, I was filling daily. This year it's sunflower seed that's disappearing quickly. I seem to have the same bird mix but the weather is very different. Would that make a difference?
nut - I find peanuts get eaten much more readily if it's cold, frosty or snowy weather. We get so much rain here that peanuts do go mouldy very quickly if there isn't an army of squirrels around to eat them.
I actually don't feed peanuts on their own at all now, I just add the nibbed ones to the seed mix.
I've been making fat balls with left over fat from cooking & these get eaten much faster than the shop bought ones. I mix the fat with ready mixed bird food but I also add raisins & chopped up bacon rind. The robins in particular love them,but that's possibly because they are put on the bird table rather than hung up.
Home made food is always better than shop bought
I say fat balls....more like fat muffins as we use those silicon muffin cases!! My kids have got really into saving fat & bits of stuff for the birds. I've found it to be something we all get involved with. Great for tearing my 12 year old son away from his PlayStation!!