Amorphophallus konjac or Voodoo Lily is a bulbous plant with a striking dark purple inflorescence.
It belongs to the family of the arum family or Araceae.
Probably originally from China but has been cultivated for centuries in Japan and other parts of Asia as a food (konjac) and medicine.
You do not want to grow this plant in the house because the inflorescence smells terribly of rotten flesh.
Although it is quite hardy, it is best to grow it in pots or raised beds because it must be dry during the rest period.
Amorphophallus konjac is a tuberous plant. The tuber can measure up to 25 cm in diameter and weigh up to 600 g. The plant grows up to 1-2 m high.
Flowering occurs in spring (April), before the appearance of the leaves, and is very short lasting. After that, the leaves appear and in autumn the plant enters a rest period.
The spadix is surrounded by a dark red to purple spathe of 30-40 cm long.
It forms a single leaf on a long, fleshy, mottled petiole. The leaf can be 1-1.5 m high. The leaves are bright green, bipinnate and deeply cut.
- Food: the tuber is starchy and processed into a brown gel, called konnyaku, which is used as a gelatin substitute.
- Medicinal: konjac was used in Japan to treat cancer but does not appear to be truly effective. It is also often suggested as an obesity control agent but this effect has not been proven either.
Elephant yam, devil’s tongue, konjak, konjaku, konnyaku potato, snake palm, voodoo lily
Amorphophallus mairei, Amorphophallus palmiformis, Amorphophallus rivieri, Amorphophallus rivieri var. konjac,Brachyspatha konjac, Conophallus konjak, Conophallus konniaku, Hydrosme rivieri, Proteinophallus rivieri Tapeinophallus rivieri
Amorphophallus: from the Greek amorphos (formless) and phallos (phallus)
Konjak: probably from the Japanese name for the plant
China, Himalayas, Philippines
USDA zone 7-10
USDA zone 6 with winter protection
Well-drained, nutrient-rich soil, a mixture of 80% soil with 20% sand. It can also be grown in a soil less medium.
Keep the substrate moist until the leaves appear. Then you can drench it everyday because growth is very fast.
Fertilize weekly during the growing season with high phosphate fertilizer 15-30-15
It grows best in a pot because it has to be dry in winter. So it is best to keep the tuber indoors in the winter, after the leaves have wilted. Ideal temperature in winter is 5-10 °C.
The easiest way to propagate is by dividing the tuber: smaller tubers appear laterally and can be removed.
Sowing is possible but it is difficult to find seed.