Don't know about 'when' in your area, but I bet you can trade for caladium bulbs if you check the Plant Exchange Forum on gardenweb.

You might also check into gardening groups/clubs in your area.

Lots of groups here have annual or semi-annual get-togethers, swaps, & sales.

Best luck!

Thanks for the idea! Supposedly I may need to wait till almost June to plant. This is a great reason to add a trade list to "My Page".