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  konjac dreamtime
From: Roger Sieloff ISDH <sieloff at doe.state.in.us> on 1997.09.03 at 06:02:51(1154)
I've had this Amorphophallus for well over six years at least,
starting with three 4" bulbs a friend gave me. Since then they have been
very fruitful (at least asexually) and multiplied many times over. For
the first two years they stayed in pots. The senario was always the same
though - plant outside in late May, sprout in mid-late June, do the
photosynthetic thing a few months and then keel over and die the second
week of October. They were dug up and stored dry. The really big one
gets used as a combination bookend/paperweight. Their tolerance of 6
months of absolute dessication is noteworthy - I wish potatos fared as
well. One thing I learned is immersion in water is fatal to them - they
tend to rot very quickly. A. konjac can't swim! Better to leave them
bone dry until one is ready to plant them. There has been some discussion
about them being hardy as far north as zone 6, but I have never seen any
"volunteers" ever sprout the following spring. Maybe they don't like
Indiana winters. One other thing I've noticed is that the tuber is
completly exhausted and subsequently replaced every season. This is seen
in the crumpled skin of the spring tuber I usually find beneith the
fall tuber when I dig them up in October. As reguards growth every year,
anything under 2" doubles in size, anything over 4" increases about 25%
and the really big ones don't appear to grow very much at all. They do
tend to offset very readily, especially the big ones. These are seen as
long, snakey "Amorphophallus pink things" which seem to be a kind of
rhizome tipped in a small, oblong tuber. Surprisingly, even these
mini-tubers survive the winter drought; receintly, I've discovered
dessication can be cut to a minimum if one uses plastic bags. Do be sure
the tiny tubers are absolutly dry, because moisture in the bag will
probably rot them. If I had to guess, I'd say dormancy is a function of
how long the leaf has been growing; either that, or perhaps it is
daylength. Whatever the reason, all of them begin to wither right on cue
every October. I go ahead and harvest everything (they now grow out front
as a kind of exotic, Vietnameese groundcover); fortunatly even the green
ones will have fully developed tubers, and the petiole can usually be
pulled from the tuber easily. Withered ones are useful in indicating
where to dig for tubers. Konjac is very seasonal in its growth;
A. paeniofolius appears to be somewhat more reluctant about "going to
bed". The latter also develops leafy offsets - konjac makes rhizomes all
summer, but they never sprout. The tubers are markedly different - konjac
is singular, rather like a tuberous bigonia. A. paeniofolius is a mass of
oblong swellings festooned in prominent warts. The petiole is different
too, my konjac tend to be smooth and have brick red blotches.
Paeniofolius has grey splotches, each boardered with tiny bumps.
A. konjac has flowered only once. The bloom began as the tuber was still
unplanted; in fact it was mostly withered by the time it went in the
ground. This tuber sprouted about three weeks after the others did, but
it still went dormant right on time. I found the flower attractive, but
self-sterile. One thing it seemed useful for was inducing seeds in a
group of Arisaema triphyllums whose had all female flowers. I must have
doubled the chromosome count, as the offspring are all very large and grow
