I get the reason why you should rotate crops, although in a small garden like we've got it's easier said than done.
I've got one raised bed with garlic currently in but which should be coming out by the end of the month. I've got leeks which I need to plant out, currently roughly pencil width, and so in an ideal world they'd follow the garlic, otherwise I'm going to be waiting for some other beds to be freed up.
Question, then, if I put the leeks where the garlic has been until recently, will that cause problems, or so long as next year I put something else in that bed will it be ok? I'd put some fresh compost and fertiliser down either way.
Basically, I'm not sure whether you need to rotate crops within a year or within successive years.