Hi Dan,

I have only been growing my Titanum for about 6 months now. You have more experience than me then.

I currently have mine positioned inside, in front of a window that gets about 3 hours of direct early afternoon light.

I have it on a heat pad set to 75 degrees F.

I fertilize it with 15-30-15 at half strength every 2 weeks or so.

I mist it at least once a day and plan to get a humidifier set up soon to keep the humidity at a more constant level.

Other than that, that is all I do for it.

This isn't much but I hope it helps.

John

I am including the content of a reply to a similar question posed on the Aroid-L mailing list:

It's my experience that they do best if actively growing kept just a little on the dry side, especially at low temperatures. If you're looking for a recipe, it would be something like "water when the top of the potting mix is dry". If you notice fungus gnats you are way to wet. Keep in mind that at 60F, wet potting soil will be significantly cooler than that depending on the humidity. At one time, I was growing about 4000 titanum from seed and, at least as juveniles, soil temperature is important in keeping them growing. Wet potting soil can be as low as 50F due to evaporation with an air temperature at 60F. The optimum soil temperature appears to be something near 80F and if it gets much higher they tend to cook. While we are talking about temperature, keep in mind that depending on where you are in the country, your water temperature can be very low during the winter. If you don't heat the water to your greenhouse, use te pid water for this species.
While dormant, I keep mine much drier than some would recommend but that's from experience as well. It is true that they will not survive out of soil, but they will, in a humid greenhouse survive just lying on top of a pot of soil (not that I recommend it). When mine go dormant, I lift the corms, clean them and inspect for superficial rot (be very careful handling the corm since the skin is very thin in this species and any damage is asking for trouble), and then repot it in loose potting soil. I don't water this species until the soil has dried to below the base of the corm and when I water I do so only around the rim of the pot. This keeps them rather dry.

If dormancy sets in early, it will typically last until the potting soil temperature gets very warm. Here in Central Florida, if dormancy sets in in December, the plants come up in July. Conversely, if the plant continues to grow through the winter and goes dormant in May or June, dormancy is very short, sometimes only two weeks.

"The above is not my personal experience, just the recent reply to an Aroid-L mailing list question"

I hope that this helps.

John

PS this is the link for the Aroid-L mailing list:

http://www.aroid.org/aroid_l/index.html