Storing Potatoes and Onions

Hope I have put this in the right place, sorry if not.

Kind friends and neighbours, have bought me large potatoes for jackets, and some white onions.    How is the best way for me to store them so that they don't grow roots.   I wouldn't like to waste them.    Thanks,  Mrs Bouquet

Last year was my first allotment season. Previously we kept potatoes (supermarket bought) in a container in a cupboard in the utility - dark and the coolest room in the house. a bag would chit before we (2 of us) could use them. I lifted potatoes in Sept last year put them in a THICK cardboard box in the shed. Used the last of them beginning of March - no chitting.

Onions (well shallots for me) in a net in the shed they lasted till they were used - a few months. I read here somewhere not to put them in the greenhouse because you only need a sunny day and the temperature can rise quite a lot and cook the onions.

Hope this helps.