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Amorphophallus konjac, a species of plant commonly known as voodoo lily, is a bizarre, easy to grow oddity that is sure spark a lot of conversation. From the unusual growth habit, to the inflorescence that smells like rotten meat, this post will teach you all about this unusual plant, as well as how to care for it. And it is easy to care for, whether you plant it in the ground (it is hardier than you’d think) or as a potted plant.
SOME INTERESTING AMORPHOPHALLUS KONJAC FACTS
Sometimes known as Amorphophallus rivierei, the accepted name for this plant is Amorphophallus konjac.
This tuberous plant is native to China and grows in wet, tropical ecosystems.
It is widely cultivated in both Japan and China for its edible tuber. Although the corm is edible, it can not be eaten raw because of the calcium oxalate crystals that are present which would sting your tongue and throat, and probably why the plant also earns the name Devil’s Tongue.
The calcium oxalate is broken down by either cooking the tuber, or drying it.
The tubers are commonly used to make into flour, jelly, cake, noodles, and more.
Other common names for the plant include Voodoo Lily, Konjaku, Konnyaku Potato, Snake Palm, and Elephant Yam.
Amorphophallus konjac is a similar species to the Corpse Plant (Amorphophallus titanum), except that konjac is much smaller, easier to grow and flower, and produces an inflorescence that is far less stinky.
GROWTH HABIT & LIFE CYCLE
This plant grows from a tuber, and as new leaves grow, the tuber will shrink in size. As the growing seasons continues, a new tuber will start to grow and take the place of the old one.
The stalk is actually the petiole, and has a beautiful mottled pattern. The leaf is actually huge and composed of numerous leaflets.
At the end of the growing season, the plant will go dormant (see the Dormancy section near the end of this post), and the plant will lose all of its foliage.
After the dormancy period, if the plant is mature enough, it will flower. The inflorescence smells like a dead animal, and this scent serves to attract its pollinators. After flowering occurs, it will start to grow a new leaf and start the cycle all over again.
These plants are hardy down to about zone 6, and I can attest to this from a friend that has grown this plant in Ohio. It comes back every year. The leaves are not tolerant of frost, but the corm should be hardy down to zone 6 as long as you avoid clay soils which will spell death for this plant in cold-winter regions.
AMORPHOPHALLUS KONJAC CARE
If you are growing this plant indoors, a good location would be either an eastern or western facing window, or even your sunniest window (south exposure if you’re in the northern hemisphere, or north exposure if you’re in the southern hemisphere), especially in the winter time.
If you choose to grow these in the ground (they are hardy down to zone 6 or so), place them in part sun and try and avoid any locations with hot, mid-day sun. A half day of sun should work well, or dappled sun throughout the day.
These are definitely moisture loving plants and appreciate being kept consistently moist while in active growth. Mine is in a pot and I water when the surface of the potting mix feels dry to the touch.
It can even tolerate standing in water while actively growing. In the Fall, when the plant starts to go dormant on its own (see the dormancy section later on in this post), you should stop watering.
This plant is a heavy feeder, so be sure to feed throughout the growing season, but halt fertilization when dormancy starts and the foliage starts to yellow and die off.
The International Aroid Society recommends a fertilizer that is high in phosphate in order to stimulate healthy tuber growth.
These plants like to stay warm, so try and keep them at a minimum of 60°F (16°C), but prefers warmer temperatures over 70°F (21°C) during the day and at least 66°F (19°C) during the night, with a range of 20-25°C (68-77°F) being an ideal growing range according to the International Aroid Society.
This plant does appreciate higher humidity, so aim to keep it at least at 60%, but it should tolerate lower as long as you keep the plant well watered.
POTTING MIX AND SOIL
Amorphophallus loves a potting mix or soil that is well-drained, fertile and moist. If you plant them in the ground, they will not tolerate heavy clay soils, especially if you live in an area where they are marginally hardy because they can rot in cold, wet winters.
In a pot, it’s much easier to control the potting mix. I have mine planted in an all-purpose potting mix to which I’ve added some perlite.
Amorphophallus konjac readily produces offsets and new tubers. It is recommended to wait until Spring time to separate any small tubers.
An unusual thing about Amorphophallus is that the roots grow from the top of the tuber, so the top of the tuber must be placed deep enough under the soil surface.
If planting in a pot, choose a pot that is at least twice the diameter of the widest part of the Amorphophallus tuber.
As far as planting depth of the tuber, plant it so that it is at least twice as deep as the tuber is high. So if your tuber is about 2 inches high, plant the tuber so that it’s about 4 inches deep (from the top of the tuber to the top of the soil line).
Dormancy will start on its own. In fact, for my own plant, within a matter of days, the foliage started to yellow and collapse. Mine started to do this about a month into the Autumn.
Wait until the leaves are fully browned before removing them. You can see one more leaf in the photo above, and it’s still somewhat green. Leave the foliage until it has turned brown before removing it.
Once your plant starts to go dormant, stop watering your plant completely.
During dormancy, either leave the tuber in its pot, or you can take it out and store it in dry peat moss. If you want to propagate, wait until the Spring time before separating any tubers.
As far as storage during dormancy, store your tubers in a cool, dark location that is around 40-50°F (approximately 5-10°C).
If you’ve kept your tubers in its original pot, wait until you see signs of new growth poking out of the potting mix before starting to water again. At this time, be sure to place your plant back in appropriate lighting.
If you’ve dug the tubers up and stored them in peat moss, inspect the periodically until you start to new new, pinkish growth coming from the top of the tuber. Then plant them as directed in the Propagation section of this post.
After the dormancy period, if your plant is mature, it will flower. If it still isn’t mature, it will start growing new foliage instead. Typically, your plant will flower when it is 3-4 years old, and the inflorescence is a gorgeous burgundy color.
Flowering will typically occur in late Spring to early Summer, and the inflorescence will be 3-4 feet tall.
But beware! The inflorescence smells like rotting flesh, and this is intended to attract carrion flies, its natural pollinators. So be careful where you have the plant when it is bloom!
When the inflorescence is ready to be pollinated, the foul stench starts, and this attracts its pollinators. Once the pollination has occured, the odor disappears.
The inflorescence has the typical aroid structure consisting of a spadix (the spike in the middle that contains numerous, tiny, male and female flowers), and the surrounding spathe (the maroon sheath).
The interesting part is that the plant will actually heat up the spadix once the pollen is ready for fertilization, and this helps to increase the foul odor which is released by the plant in order to attract pollinating insects.
After blooming, the plant will start to throw out foliage growth, which can reach up to 4-5 feet tall under good conditions.
Do you have an Amorphophallus konjac? Comment below. I’d love to hear!
Monday 27th of February 2023
Hey, Amazing article and read! Thanks for the info. I'm in the UK and growing it in a pot. Finally mine is putting out a flower. Do you know how long they normally take to grow and develop before they open? Thanks.
Tuesday 28th of February 2023
Glad you enjoyed the post Alex! It can vary a lot depending on your conditions. Mine is still dormant and I need to check on it and notice how long it takes for me. Sorry I couldn't provide a more concrete answer!
Tuesday 31st of January 2023
Hello & Happy Tuesday! I have a 20 year old konjac that's currently in a pot, however it hasn't always been. I was searching for why it might be sending up two tubers when I found your site. I picked your site because I was born and raised in Cincinnati, Ohio and moved away in 2008. I purchased my Momma Voodo bulb at the time smaller than my fist, from the Krohn Conservatory during a butterfly show in 2004. She grew and populated two different yards (6" deep in good soil, surviving winters) in Cincinnati. I then moved to D.C. for three years where she stayed potted but next to a huge west facing window. In Nashville, she was in the ground for 3 years and potted for 3 years. In the ground she grew huge with over a four foot spread and 8" bulb. She shrank to about 6" whilst in a pot. Now, Here in Albuquerque, New Mexico she's been in a 2' pot for the past 5 years. She really can't be in direct sunlight at all here, the sun is insane, so she usually breaks ground indoors (like she is now with two tubers and 4 kids) and then I put her underneath a big tree with daily watering when it's warm enough. She's bloomed several times, once in Nashville and once here in ABQ two years ago. She bloomed indoors two years ago... wow was that hard to handle! Thankfully it was getting warm outside so I was able to take her out when she got really putrid. They're really beautiful plants & this girl will continue to go with me if I ever move away from here. But anyway sorry for the story but I thought you'd find it fun. Now my question is, you may have guessed, do you have any ideas why now, at 20 years old she decided to grow two tubers which are neither flowers but both leaf? There hasn't been any tubers growing that close to Momma (within a 6-8" radius) ever before so I don't believe it to be a child. Whilst googling I have seen pictures of a konjac with two tubers, but with one a leaf and one a flower. Any ideas? Thank you very much in advance, may your day be awesome! Namaste, Sean
Thursday 2nd of February 2023
Hi Sean! I love that story! Thanks for sharing! I'm actually not sure of the answer to your question. But when I received my plant, it was sent to me by one of my readers and it did have multiple tubers in a cluster all together. It sounds like you're doing a great job with your plant so just keep doing what you're doing :-)