Hi Bob, I've only grown maybe a half-dozen species from seed and always just potted them up and let them grow naturally so can not really answer your question, but I would pot them up and let them go. By the way, you will likely get multiple petioles this first year and they may grow continuously for a much longer time than you are used to....let them grow as long as they want to develop as much tuber as possible :o) Dan

Bob , I have tried that sp. a few times , it is not suited to the tropics . Looks very nice though . I would put several seeds into a 150mm and treat as any normal plant . Once sprouted and growing feed up well to get maximum tuber size . Dan has better experience growing out of the tropics .

I have A. kiusanus that went to seed in 2006. I let the seed ripen, then I sowed in pots, kept indoors during winter. This spring nothing was sprouting and I grow Arisaemas from seed, so I dumped the soil from the pots into the Arisaema seed starting tray. I use plastic window boxes due to amount of seeds.
The Arisaemas sprouted and have a simple leaf and others showed a leaf like a mature Arisaema consanguinum. I thought I had something unusual as I FORGOT that I dumped the soil from the A. kiusanus pots in the Arisaema seed starter tray.
The A. kiusanus grew extra leaves and I realized that I did dump the soil into the seed starting tray. I know that Arisaema only put up one leaf as seedlings(??)
The A. kiusanus are still growing and the stems look like the Adults that I grow.

The moral is ~ Remember where you put old seed as they may still come up!!!

Good story KrazyAroider!! A lesson for all of us :o)

Yes, Arisaema only produce a single simple leaf the first year unlike an Amorph that produces multiple petioles before going dormant :o) Dan