[harry]

I inherited a couple of asparagus beds with my allotment but want to dig one up, when is the best time to move one of the crowns

[Trillium]

You'll find a lot more than one crown per bed. If you really don't want them, then dig them up anytime. The root mass will be too large to move successfully if you hope to give them away. If the bed is a fairly young one, then wait until fall when the plants go dormant.