I grow Arum italicum and had some planted on the east side of my house so they are in full sun until about 12:00 pm and then in shade the rest of the day. Mine start putting out new leaves when it starts to cool off in early fall and will bloom in early spring, usually in March. When it starts to get hot they die back and become dormant until the weather gets cool again. They are planted very close to the house and the Tn. clay stays fairly dry there but they seem very happy and have multiplied. I'm not sure if they would grow in soil that stays wet a lot. Maybe someone else could help you with that. Mine are dormant and I actually dug them last week to thin them and possibly get rid of a few. Do you have anything you would like to trade? I didn't see anything on your trade list. Let me know.
Jim

Sorry,

Don't have anything to trade.

In San Antonio, soils tend to be quite dry. I was implying that I would need to water them to get them started.

It seems that the Arum is popular in the Carolinas, especially North Carolina and along the eastern US. Howewever, I don't see any reference to it growing in Florida.

Southern Living has heat zone recommendation for Arum Italicum as maximum of heat zone 9. Most of the Carolinas are in heat zone 8. I live in heat zone 10. (However, heat zone 9 plants do survive in summer shade here. The Arums would be in full summer shade, winter part sun)

The heat zone is different from the USDA hardiness. It is based on the number of days over 86 degrees per year. In San Antonio, that's about 160 days per year. Same is for most of Florida.

Since many bulbs need a certain amount of "winter chill", I wonder if this is one of them?

There are bulbs that thrive in high heat zones and need no winter chill, such as elephant ears, canna, caladiums etc.

Bulbs that require winter chill are tulips, crocus don't make it here. Even many of the daffodils don't do well here.

Anyway, I wonder what if there is a "winter chill" length requirement for Arum Italicum?

Winter chill doesn't necessarily mean freezing. It may have to do with number of days/hours less than 60 degrees.
(Or hours/days with soil temperature less than 70 degrees or 60 degrees.)

I wonder if climate is "too warm", the poor plants may have trouble breaking dormancy in the fall?

Generally, in San Antonio, the entire month of October is 80 degrees and above.

I know that Arums can grow in frost free environments such as northern California, but they have year round "cool" weather, with very few days with any weather over 80 degrees.