I have had good luck with my Amorphophallus Konjac, all four bloomed this year.
When I bought them they were 2in across, next year 5in, next year 9in and 14lb... bloomed in the early summer.
Two plants were polinated by the flies, who is the daddy? I do not know, but I plan on sowing the seeds to try and find out.

I use a high quality potting soil, lots of sun, water and MSU fertilizer at 150ppm (as that is what I had on hand). Mine needed an ocasional spray to control mites and I had to pick off japanese beetles. At the end of summer the grey furry tree rats broke up the foliage.

YIPEE! It looks like it might be coming into bloom, the spike's elongated about 1/2" in the last 5 days. I realised that it might be too cold in the basement where I'd been storing them, so I put it in the bedroom next to the air register where its 10 or 15 degrees warmer.

Now all I have to do is protect it from my wife. I keep telling her it doesn't smell too strong until the flower begins to fade. ;-)

Mine has flowered for the last couple of years.. It's about to open the bud again this year.. The wife told me to take it outside, so I snuck it into a bathroom. Last night I was complaining that the cat had urinated on the floor.. I thought we'd need to take him to the vet, cause this was STRONG and stunk! BAD!

turned out to be the konjak...