In article ,
David wrote:

I have some large pots with shrubs, trees, etc.

I would like to be able to stand them in a container of water so that I
can thoroughly soak them when required. Needs to be deep enough to come a
reasonable distance up the post so water is likely to soak in quickly.

I have had a plasterer's bath for about 20 years - sits propped behind
the greenhouse when not in use. Have used it for a dozen different
purposes, one of which might even have been mixing plaster. Invaluable,
and fits your bill perfectly I'd have thought.

Cheers
J.