How to Care for Amorphophallus Gigas

Posted by Shop Wildpretii on December 15, 2023

In Sumatra Indonesia, there are 2 climatic cycles, a dry period and a wet period.

Watering: Amorphophallus Gigas love water while leafing and during their wet season in West Sumatra. They typically grow year-round with intermittent 'rest periods'. Water frequently during their leafing cycle and during their wet season. Keep dry during their dry season and only water intermittently after the soil is slightly dry. Fertilize regularly for best results.

Soil: Amorphophallus Gigas, like many other Aroids, love to be in chunky soil. An ideal consistency for these types of plants is an approximate blend of 50/10/20/10 (Perlite/Sand/Coco Bark/Coco Coir respectively).

**We offer a refined selection of potting medium curated for this specie. It includes a rich mix of nutrients, including an instant release fertilizer, slow release fertilizer, fungicide as well as robust rooting inoculants to help keep this plant nourished all season long. Shop our specialized blends for this specie HERE!

**Do not underestimate how quickly these tubers can rot and infect the entire corm quickly and irreparably. It is more likely that one can lose a corm due to rotting, bacterial and/or viral fungi than dehydration.

Climate: Amorphophallus Gigas originate throughout Sumatra, Indonesia. In Sumatra, temperatures average between 72-82 degrees daily. There is a wet season (roughly Sept-Feb) and dry season (alternatively). During the dry season in Sumatra, it is important to note that the average rainfall is between 3-5 inches. The downpours are typically shorter and less frequent. Therefore, allowing the soil to slightly dry out between waterings during the dry season is preferred for this specie.

These tubers can rot very easily with very rich organic soil (especially during their dry season and/or resting period).

In cultivation, while Gigas are leafing, they typically aren’t too fussy about the soil they grow in as long as it has good drainage. During the dry season, on the other hand, they are very particular and need extremely porous soil. Amorphophallus Gigas have a ‘resting’ period where they are not as active, but they are still growing, they are technically active year round (just not leafing). When actively leafing, they love a lot of water. Sometimes, it can be unpredictable whether a tuber will be resting on a wet or dry season; Therefore, it is safer to pot these in a porous mix year round. A chunky blend of 50/10/20/10 mix of Perlite/Sand/Coco bark/Coco Coir respectively is what we use.

*The goal for Amorphophallus Gigas Care is to keep these tubers hydrated without being consistently immersed in wet moisture during the dry season and/or resting period.

Sun: These specie prefer light to medium sun and a humid environment.

Treatment: When a soft spot is detected, carve out the soft infected areas up until you see only fresh flesh of the corm. Then brush over Sulfur Fungicide Powder and leave in a sunny area so the wound(s) can dry and scarify quickly. Be sure to keep away from potential pest infestations.

If you find that some spots are taking longer to dry and have any concerns whether it may still be compromised, carve back that area as quickly as possible and repeat the treatment process in that area. Once, the wounded areas are completely firm dry, the tuber can be returned to the soil.

Amorphophallus Gigas

Amorphophallus Gigas is native to the lowland rainforests of Sumatra. Formerly known as Amorphophallus Brooksii, this specie boasts an inflorescence with a very large spadix surrounded by a proportionally large spathe upon a stalk which in total can reach up to 11 ft 4 in ( 3.4 meters) in height. Amorphophallus Gigas is known for having the tallest inflorescences in the world. The leaf of A. Gigas can reach a height of 14 feet tall. The tuber or corm is second in size to Amorphophallus Titanum at up to 154 pounds (70 kilograms) in weight.

Photo referenced: Amorphophallus Gigas Inflorescence

Amorphophallus Gigas is a close relative to Amorphophallus Decus-Silvae. Both share visibly distinct leaflets, inflorescence and at times visually similar petioles as well. Amorphophallus Gigas from Northern Sumatra has distinctively thin, dark spadices that are black/purple. Whereas, Gigas specimens from Central and South Sumatra are pale pink/yellow, more similarly to the Petiole of Amorphophallus Decus-Silvae. Other than geographic location, the northern form is more distinct in contrast to Central and South Sumatra. Other than some minor variations, Gigas and Decus-Silvae share the most similarities in comparison to other Amophophallus species.

With Amorphophallus Gigas, there is no pronounced dormancy. Just like A. Titanum and A. Prainii, Gigas keeps going and going. This specie has been seen to survive through nights with tempuratures dropping in the low 40's in Fahrenheit, without losing it's leaf. Amorphophallus Gigas prefers relatively more humidity compared to A. Titanum. With similar symptoms as Amorphophallus Odoratus, the leaflets tend to curl down with insufficient humidity.

Photo referenced: Amorphophallus Gigas Lea f

**Below is a map that show Sumatra, Indonesia where Amorphophallus Gigas can be found. For your convenience, we provided a large image so it can be zoomed in.

After blooming, the flower dies back and a single leaf, which reaches the size of a small tree, grows from the corm. The leaf grows on a tall stalk that branches into three sections at the top, each containing many leaflets.

Each year, the old leaf dies and a new one grows in its place. When the corm has stored enough energy, it will on occasion, rest for about four months. Then the process repeats.