[kermit]

Once again this year, I have a load of very large containers / sacks with 1st / 2nd earlies in them, coming on great.  Ive run out of compost and loathe to go and buy more.  Do you think I could just keep topping up the containers with some 2-3 year old well-rotted horse manure or do they need other nutrients / soil structure?  Ive loads of manure left.

[solway cropper]

You could bung just about anything in. If they had a good depth of compost to start with all you are doing is keeping the light off the tubers to stop them greening. I'm using leaf mould mixed with lawn clippings. Other people just use scrunched up newspaper!!

They will need feeding though. Something high in potash like tomato feed is ideal.