Amorphophallus konjac, the Voodoo Lily

Obviously, there are many plants in the gardens here, but some of them are more special to me than others. These are the plants I dug up in October 2020 and brought to Pennsylvania: Asiatic lily bulbs and Amorphophallus konjac (tubers and seeds in seed trays). Our friend and botanist Frank Watson gave me a single tuber sometime around 2017, and that tuber had developed into multiple plants by the time we moved. The original tuber grew so large that it produced three flowers (inflorescence) in the summer of 2020. The plants loved the sandy, well-drained soil on Maryland’s eastern shore.

Flower spike 2018
Flower 2018
Flower spike 2018
May 2019
May 2019
July 2019
Flowers 2020
Three flowers, 2020

In these photos from Maryland, you can see the inflorescence and how the small leaves pop up in May. These are offsets, tiny tubers with their own leaves produced from the original. By July, the leaves approach full size for the season. If a plant is going to bloom that year, the inflorescence always precedes the leaf. But an inflorescence doesn’t appear every year—the plant only blooms when the tubers are large enough and have stored enough energy. Although a leaf may follow a flower in the same season, I’ve never had that happen. The plant itself is a single leaf. On an established tuber, the inflorescence spikes and leaves are easily as tall as I am. No jokes here, I know how tall I am!

Summer 2020, seeds on flower spike.

By our last summer in Maryland, I had about 20 offsets, and one inflorescence of the three was successfully pollinated and produced seed. I allowed the seeds to turn red and then planted them in a large tray before we left for PA. I eventually had more than 100 seedlings plus the tubers I dug up to bring with me.

The genus name Amorphophallus comes from the Greek amorphos meaning shapeless or deformed and phallus meaning penis. The specific epithet konjac comes from the colloquial name for the plant and the starchy food made from the tubers. The konjac is also called devil’s tongue, voodoo lily, konjaku, or konnyaku. It’s a herbaceous perennial native to forest margins and open thickets in the Yunnan Province of China. It’s cultivated around the world as an ornamental and as a food crop in East Asia. The round, flattened tubers can reach up to 11″ in diameter and will spread through offsets. The tubers produce a single, highly divided leaf with a pale pink stem mottled with olive green splotches. This petiole can reach 4′-5′ tall, and the leaf blade can reach up to 4′ across. When the tubers reach maturity, they produce an inflorescence before the leaf emerges. The inflorescence is made up of a dense, spike-like spadix that bears numerous, small, male and female flowers and a leafy, dark maroon to purple-brown spathe with ruffled margins. The 3′-4′ tall bloom emits a strong odor of rotten flesh to attract pollinators. Not surprisingly, the voodoo lily is pollinated by flies. I learned not to garden downwind when they are in flower! Leaves appear in May, and the plant dies back completely after the first frost.

First summer in PA
Second summer in PA, already lots of offsets

I stored the tubers over the winter and planted them as soon as the soil warmed up in the spring of 2021. I was concerned that the plants would not survive the colder PA winters and our heavy clay soil. I was thrilled when they all came up, and I’ve been even more pleased to see the plants grow larger each year and produce more and more offsets. I could dig them all up and store the tubers inside each year, but I’m lazy, and their fate gives me something to stress about every spring!

Large leaf emerging
Small leaves of Amorphophallus konjac
Growing Amorphophallus konjac
Growing plants

I always worry that the winter was too cold or too wet, and I hover over the herb garden daily, looking for the little penises to pop up. The konjacs grow happily among the sage, thyme, and Don Juan climbing rose. Last summer, I had 37 plants, and many of them were more than 5′ tall.