That's really helpful, thanks.

Is that the Complete Seed and Nut mix, or one of the other many types they have? So much choice

Besides Tundra, I've also grown Marshall's Winter Green but that's a pointy one 

As per the title - I used to get the Wilko bird seed from the stores, but they've now shut.

I have various small birds in the garden - coal tits, great tits, sparrows mainly at the feeder I use.

Where do you get your bird seed from? Preferably the pre-mixed type as I don't have room to store lots of different ones and mix them up.

They've clearly learnt some tricks from their Yorkshire cousins 

I had a plastic tube bird feeder which has the two holes near the bottom with plastic dowels for birds to perch on. The squirrels left it alone for ages, then worked out how to nibble the surrounds of the holes so that they fell out, letting the seed out too. 

I replaced it - they'd done the same within about 48 hours 

I re-replaced it, but this time with a far more expensive metal one with the RSPB label on it and a surrounding wire cage that the birds can get through. They have tried to work out how to get in (as have the pigeons  ) but to no avail yet 

I'm tempted to put my ones in the PT out over the weekend but even cautious about this.

Mine have been planted in the greenhouse border for a few days now, if the forecast shows any low temps I'll drape them in fleece, to be on the safe side