Tropical, when I was doing my research on titanum the two big things that stuck in my mind were that it's very susceptible to nematodes, and also susceptible to fungus. Then I found out that we do have a lot of nematodes here, and fungus, of course, is everywhere. So I followed the recommendation and got a good mix of organic soil, ran fungicide through it, and then washed it through with clean water. All this before getting the tuber. The pot I sat out under a big ficus because they don't drop branches. When the titanum was in and growing I watched it like a hawk.
It started early spring, just before our build-up season. In the build-up it began to wilt a bit despite only getting filtered sun through the trees. So I put a bit of a canopy over it to give complete shade and it looked better. The wet season came and I reduced watering. It grew right through. Come autumn (wet season over) it kept going. And then right through winter as well. No one told me they'd just keep going. Then early spring I came home from work and there was the shrivelled stem of the titanum laying against the tree. Left it a few weeks for the tuber to withdraw all nutrients then dug it out. The tuber looked good. I got another lot of organic soil but this time I put limestone gravel in the bottom of the pot. One text had that they grow in the leaf litter on limestone rock in Sumatra. I repotted and waited.
Every month or so I checked the tuber but no sign of growth. Right through the summer (wet season) it just stayed dormant. Come winter it stayed dormant. Finally early spring it started off again. One year later, almost to the day. The young plants I started off from seed and they're about 15 months old now. They say about 7 or 8 years to flowering. There's a lot of caring to be done with those. But if you're getting titanum, be sure to do all the research you can. Mine are outdoors all the time so they have their own set of particular requirements and problems. You'll have to be keeping yours indoors and that will have its own set of problems. It's a challenge but I think it's worth it. Anyway, that's what's keeping me going, I want to flower mine.
I did an article on Amorphs on another site some time ago. You might find it interesting:
http://cubits.org/Jungle/articles/view/791/