I grew these for the first time this year in Tucson, AZ. They were a little smaller than expected, but I think it was my fault - I tried to train them on a new trellis once they had already grown considerably, which was not good for the vines. My original trellis was not nearly big enough - the vines got really long. So, in my attempt to "restring" them, I think I damaged the vines. I will definitely try them again next year, but I'll either let them grow on the ground or let them grow against a taller wall with something taller to climb.
They got morning and afternoon sun (which is intense in the desert) and were on drip irrigation. I planted in late June, but could probably plant a little earlier with regular water.
The Rad part - I really do have tin y little luffas, that if were bigger would be perfect for scrubbing pots and pans- they are a little coarse for your skin.