Sandy I know what you mean I was suppose to strip wall paper and paint this spring and summer but worked on the garden instead. Figured I could work on that when it gets cold.
I use fafard #51 or #52 which I purchase at a discount from
http://www.hummert.com/
It is bark based potting medium. It is fabulous for everything except my succulents. Very well drained and I had to water my containers everyday and twice when temps got over 100. For my succulent type plants I add sand and gravel. Not that successful and tried cactus potting mix which was much better but I'm gonna take some good notes from the succulent cubits this winter and try potting them up in better medium.
We have a local tropical propagator and she recommended fafard + osmocote slow release fertilizer then blue stuff (miracle grow, peters grow, or whatever is available in your area) at half strength once a week. That has been extremely successful for me.
With the above combination and all the 100 degree days this summer my tropicals were premo.
This was my first year with caladiums gave it a try cause I hit a big dollar sale of 4" pots. I was also gifted some bulbs from KATG in June and it was so hot here they took off like wildfire. It was the first time I ever planted caladium bulbs and considering my success I would buy from her resource in a heartbeat. Caladiums 4 less
http://www.caladiumbulbs4less..... My local extension service tracks ground temperatures. The caladiums, elephant ears and such really don't perform very well till it is consistently 60 degrees at night and the soil warms up. It is not worth the trouble and mess for me to start early indoors, just requires patience till it gets hot enough.