Allotments 4 All

I have a few kilos of King Eddies in a hessian sack being kept in a cool garage. Went to use them this evening and have found a few of them with single sprouts on them, about 2 inches long. They've only been in the sack for about 3 weeks, what have I done wrong?

I would guess they're too warm, but could they be a little too humid too?  Did you harvest them on a sunny day and leave them on the surface for a couple of hours to dry?

Better check mine tomorrow... mine are in hessian and covered with carpeting in the shed... Watch this space..