Re: Flowering in konjac
Having done this several times, I can answer both your questions.
When you plant the tuber in the spring (??), the tuber puts out roots
from the top surface of the tuber and a shoot from the top, center of the
tuber. This shoot grows to becomes the plant. One big umbrella shaped
leaf. That pretty much consumes the tuber so the size of the old tuber
controls the size of the new plant. The plant then grows a new tuber
(usually with the remains of the old tuber stuck to the bottom). The
size of the plant and the growing conditions control how big the new
tuber becomes. Under good conditions, the weight might double. Then the
plant wilts and falls off in the fall. Inside the bottom of the stalk of
the plant you will find a conical 'bud'. If this bud is somewhat pointed
with slightly concave sides, it will become a new plant the next year.
If it is rounded on top with slightly rounded sides, it will become a
'flower'. Usually the tuber has to be about 1Kg before it will have a
flower. There is not enough light inside the house to increase the size
of the tuber much, so they will seldom flower inside. I grow mine in
full sun and they usually more than double. There are exceptions. Last
year I had one that looked sort of like a plant bud but it turned out to
be a flower. Also, a tuber that I expected to double in size got only
slightly larger, though it did have a flower as expected.
You don't have to have the Konjac planted in the winter to have it
flower, since it doesn't have any roots at all. Mine sits calmly in the
cellar on a shelf until the bud gets a couple inches long. Then I bring
it upstairs and it sits in a basket on the floor while the flower grows
taller by the day. On evening it grew a couple of inches while we were
having dinner with friends nearby. It took about 3 weeks to grow over 7
feet tall. The flower weighed 5 pounds. And the 13 pound tuber ended up
weighing 8 pounds. This year I cut the flower bud off my largest tuber
(sigh) so that I could start the season earlier with an unshrunken tuber
(16 pounds) so the plant will grow larger this summer. BTW - I tried
this with an A. Saurmatum and the flower dried up just before it opened.