A. konjac doesn't seem to like it in the ground at my place. But I did put A. bulbifer in and it's spread like a weed and now there are hundreds of plants. The smell of one inflorescence isn't too bad but when 6 or 8 plants are flowering simultaneously it gets a bit much. When those die off more keep flowering over the months. I've started pulling a lot out to reduce them. I have A. paeoniifolius in the ground too but it clumps and doesn't spread all over the place. Amorphs all look nice, but some have their down side.

I had A. bulbifer one year from a seller who sent me tubers of it instead of Arisaema concinnum which they were said to be. Unfortunately, it was not quite able to survive our climate and died the first Winter. Bulbils it had produced were potted and placed out next Spring and they too died when winter came. Seems as if konjac is the only one which will survive garden growing here.

Do you have a pic? I grow mine in containers and bring in the bulbs every fall. Mine bloom regularly, even last year when my largest split. Perhaps they need a little warmth to bloom.

Sorry, can't get a photo this year because we just had three immense trees removed and the falling debris from this work has stripped off all the leaves. All that remains is a few of the denuded stems. Not a worry to me as they would have been killed off with the first frost which is expected most any day now.,

They need rich soil and fertilising to flower well. So when they're in the ground they tend to lose out to invading roots from other plants. In pots they have no competing roots and are easier to flower. But they will eventually flower in the ground, it just takes them longer to build up what they need to accomplish it.