... you can easily throw together a "pool for pennies"!
Well, actually it won't be a pool for pennies themselves, save your pennies in a jar so you can buy plants and seeds next year!
I have so many potted nursery plants I made a couple of "pools" and use them as Vic suggested except I use them regularly, not when I go out of town. I laid down some landscape timbers in a rectangle (available inexpensively at box stores) and lined it with plastic. The pool is only about 4" inches high but with all my pots in it that is plenty. What's even better is when I water the pots the excess water collects in the plastic-lined enclosure, not draining out onto the ground and disappearing. The best part is as the soil in the pots dry out the water is then wicked back up into the pots. This REALLY cuts down on the number of times I have to water as well as cutting down on water usage. Just as importantly it cuts down on the time needed to water, letting me go do more pleasant tasks...or just taking time to enjoy other things in the garden!
Good tip, Vic!
Shoe
Photo: taken a couple years ago but in the foreground, behind the cinder blocks, you can see a plastic-lined pool made from landscape timbers. You could easily just use what you have laying around for the sides though...bricks, fallen tree limbs (or firewood pieces), etc