Thanks for that BAK, that's a bit of reassurance for me - as I also don't get to the plot every day.
I've been giving this some thought and thinking about the needs of the celery I'm going to try the self blanching variety (I think I have enough work cut out with earthing up spuds..) and will create a trench for them with lots of well rotted manure / anything else organic I can get my mitts on, and then mulch with manure / grass / straw. Where I did this on the dwarf beans this year the ground underneath the roots etc was still damp, whereas other areas on my plot were bone dry.
Thanks again
1066