Hi Skip - there are others with lots more knowledge than me on list but having just had this happen here in the UK: watch out!
Depending on the temperature regime at which it has been stored at this time of the year and in long that size of tuber you could well be looking at a flower spike rather than a leaf spike. It's fair to say that letting A. konjac flower in the house is not for the faint hearted, or those wishing for domestic harmony.
In a desperate attempt to save both my relationship *and* the konjac I bundled a trash bag over the flower once it had unfurled, fastened it right around the stalk with masking tape, and then double bagged it in the same way. This did quite a good job of limiting the smell to the room in which it was in, but it's a noticeable addition to the household odour even still.
I'm not actually sure it's necessary, but in advance of flowering I did put the tube in a pot of peat-free compost, which I occasionally watered very lightly.
Of course, if it is a normal leaf spike, then you will need to put it up and keep it well watered and fed if necessary. With the tuber of that size, you're looking at a very significant growth, and I think it's may well dwarf most rooms in most houses. In my experience they don't need, or even really like, very bright sunlight, so moving it away from the window would probably be plausible, although you will find it will bend towards the light.
Hello. I recently purchased a very large Konjac. It’s about 18” across. I have it in a nice, dry box near a window. Well it’s starting to shoot! The growth is about 9 inches right now.
I live in Northern CA and right now it’s wet and cold. There is no way I’m potting this now and putting it out. So, what should I do with it? Should I can pot it now and keep it inside or should I just leave it in the box and watch the magic?
Any help would be greatly appreciated.