how to grow potatoes in bag

Ive just found some Carra seed potatoes in my shed today that i had forgotten about, unfortunately i have no space on my allotment to plant out. I recently read on the forum that it was ok to grow spuds in compost bags. I havent tried this method before, so any advice would be appreciated.

You need to get them in now-put about 8 inches of soil/compost-plant tuber and keep  adding more soil as it grows -start with bag rolled down then unroll as you go and top up with soil.

Hopefully that makes sense-obviously keep well watered and pierce holes for drainage.

Thanks Geoff but how many shall i plant in the bag I really dont want to discard these.

3/4- how many have you got?

Six or seven  would it be ok to layer them it is a large bag.If not, I can start another bag Thanks for your advice 

I would use two bags for the best result.

Cheers They will be tomorrow.

I recently bought the potato bag offer in the Gardeners World package (paid postage only, it was a brilliant offer...seed potatos, potato bag, 5 packets of seeds and a pair of gloves all for £4.95) anyway my potatos didn't seem to do anything for a couple of weeks but now they are like triffids lol..I covered them in soil and within two days they needed doing again and again and again...now they are at the top of the bag and I can't wait to lift one, talking of which does anyone know how long I have to leave them before I lift any? thanks in advance

As a general rule -wait till they have flowered-but it does depend on the variety.

Be patient

someone at work has just said to let the green part of the plant die before lifting, anyone know if that is correct ?? thanks in advance

That advice is for maincrop-what variety are you growing-it would be helpful to know.

lol..what a stupid person i am..it wasn't with the GW magazine it was with Sainsburys lol..blimey its been a long day at work.  I'll have to check with variety they are tonight, sorry for giving you false information.

ok i checked last night and their Charlotte potatoes, any ideas please

Charlotte-2nd early-you should be able to harvest some when the flowers have faded.

excellent, thank you so much for your help