konjac dreamtime

From: Roger Sieloff ISDH <sieloff at doe.state.in.us> on 1997.09.03 at 13:02:51(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 enthuiastically. +More Roger L. Sieloff

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