Allotments 4 All

It's our first season, and we are trying to plan the lottie...
We have 4 beds to plant. We have put onions in bed one, and we are wondering when we should rotate the onions out of this bed into the next...is it after these are harvested or after the autumn planted onions are harvested next year?
thanks

Harvest your onions from e.g. bed 1 in autumn, and plant the new 'uns in bed 2. Does that make sense?
If you do a search on 'crop rotation' here there has been a good deal of useful input e.g.
http://www.allotments4all.co.uk/joomla/component/option,com_smf/Itemid,57/topic,14631.0
http://www.allotments4all.co.uk/joomla/component/option,com_smf/Itemid,57/topic,16945.0

cheers super, am getting myself a bit muddled methinks. Just wanted to check if the rotation happens at end of year or season or when!!!

You can get good  info from the hdra website too. It all works on an annual basis initially: one year then everything moves round. My rotation is: pots, roots, legs, bras, but there are other possibilities.