How to Care for Alocasia infernalis (Black Magic)

Alocasia infernalis plants

The Alocasia infernalis (also known as Black Magic) is a must-have if you are into collecting rare plants. In this care guide, you will learn exactly how to grow and care for this special Alocasia.

In the right light conditions, the leaves of the “Black Panther” will amaze you with their shimmery metallic black-purple reddish gleam which will deepen as the plant matures. On top of that, these arrow-shaped leaves have big veins all over them.

This exotic house plant is native to Southeast Malaysia Eastern Forest and has earned its nickname because of its black leaves. It will grow to about 22 inches (55cm) tall with leaves growing to about 6 inches (15cm) wide. Because it’s a small plant, it can easily be grown in a terrarium. or under a small grow light.

To fully understand this plant, here are the best tips and tricks that you can use, including how to water the plant, the best soil to use, what fertilizer to use, what environment it likes, and how to propagate it.

Images by Ashley Reichwein from FancyPlantsyLLC.

Alocasia infernalis pinterest

Summary:

  • Light: Bright indirect sunlight
  • Water: Only water when the top 2 inches of the soil are dry
  • Soil: Well-draining potting soil
  • Fertilizer: Once every month (only in spring and summer)
  • Size: The plant grows up to 22″ (55 cm) tall
  • Size: The plant’s leaves grow up to 6″ (15 cm) long
  • Temperature: Between 65 and 75ºF (18 and 24ºC)
  • Humidity: At least 60%
  • Cold hardy: Not cold hardy
  • Propagation: By division, offsets, and seeds
  • Toxicity: Toxic to humans and animals

General Care for Alocasia infernalis (Black Magic)

The Alocasia infernalis is not the easiest plant to grow and care for because it has very specific needs. When one of these needs is not taken care of correctly, the plant will have trouble growing. In this care guide, I will tell you exactly how you should care for your “Black Magic”.

Light

To keep the Alocasia infernalis happy and provide it with the right amount of light, you want to make sure that it receives medium to bright indirect sunlight (no direct sunlight).

If it receives direct sunlight, the leaves will start to burn, turn brown and crispy. Unless you want to serve Alocasia crisp at dinner (not recommended), it’s best to keep the “Black Magic” away from direct sunlight.

If the “Black Magic” does not receive enough sunlight, the plant will quickly start drooping. This means you have to place it in a spot where it receives more light. A North-facing window would be a great place to grow this plant.

Water

This plant is really a drama queen when it comes to watering. As a rule of thumb, you only want to water this plant when the top 2 inches of the soil are dry. This equals to watering once every 6-7 days. However, in the winter months, this plant needs a lot less water.

Overwater the “Black Magic” will promote root rot. Root rot is a common problem and occurs when the roots are not able to take in oxygen. Over time, the roots will die and so will the plant. This is why you always want to water carefully.

Underwatering the “Black Magic” will result in browning of the leaf tips. Letting the soil dry out completely in between waterings can make the leaves of the plant fall off. Also being inconsistent with waterings can result in yellow spots on the leaves.

An EASY method that I use to give my Alocasia plants exactly the amount of water that they need is by using a moisture probe. This probe will indicate how much moisture there is in the soil. For the Alocasia infernalis, when the moisture probe gets to about 2, it’s time to water the plant. Click here to check out the moisture probe on Etsy.

Repotting & Soil

When it comes to repotting, the “Black Magic” likes to be slightly root-bound. Since the plant doesn’t grow very tall, it only needs repotting every few years.

When it’s time for repotting, in the early spring, look at the bottom of the pot. If you can see the roots of the plant through the drainage holes of the pot, it’s definitely time to transport the plant into a bigger pot. Usually, 1 inch bigger pot is good enough for this plant.

Plant in a well-draining soil mix that also has the ability to retain water. The perfect soil mix would be a mixture of perlite, coarse potting sand, and peat (1:1:1). If you don’t have these ingredients at home, you can also choose to use a premade well-draining aroid mix.

Fertilizer

The “Black Magic” is not a heavy feeder. In fact, it only needs fertilizer once every month at most. Also make sure to never use fertilizer in the winter months, as the plant needs fewer nutrients in that period and the overload of nutrients can damage the plant or in the worst case even kill it. I always dilute the fertilizer to half its strength before giving it to my plants so I never use too much. Less is more!

Humidity

Just like all the other Alocasias, the Alocasia infernalis likes high humidity environments. This is because the plant naturally grows in a tropical region where the temperature is high and the air very humid. Maintaining this plant, you want to aim for at least 60% humidity but the higher you go the better the plant will grow.

When you are seeing brown around all the edges of the leaves, this might be a sign of low humidity.

In the winter, the air is much dryer than in the summer. To make sure the air is humid enough during the colder seasons, you definitely want to use a humidifier, mister, or spray bottle. Using these tools will make sure the plant is happy.

Common pests

The Alocasia infernalis is known to have problems with different kinds of pests like spider mites and mealybugs. The biggest reason why you are having pests problems with this plant is because of low humidity.

One way to prevent pests on your “Black Magic” is to always make sure that the humidity around the plant is at least 60%, but higher is better. Pests can also be prevented by carefully washing the leaves of the plant every 1-2 weeks with a washcloth and warm water.

If a pest has already infected the plant, you can use a chemical or organic pesticide to get rid of the pest. Check out my shop where I have listed a great organic pesticide with neem oil.

if you like rare Alocasia plants, check out the SUPER rare Alocasia azlanii!

Alocasia infernalis leaf

How to Propagate Alocasia infernalis (Black Magic)

Propagating the Alocasia infernalis can be done by either division, offsets, or seeds. Propagating this plant by division is probably the easiest and most successful way. Propagation can best be done in early spring when it’s time to repot the plant.

Division

For this method of propagation, you want to take the “Black Magic” out of its pot and split the rhizome using a sharp knife. Be sure that there are plenty of roots on both parts. Next, use a well-draining soil mix (as mentioned in this article) and plant the divided plant in a pot with drainage holes.

Now care for the plant like you used to and enjoy your propagated beauty!

Offsets

The Alocasia infernalis can also be propagated by offsets, which grow throughout the whole year and are actually baby versions of the plant. If you use this method you only have to cut the roots that are connected to the mother plant. The best way to do this is by using a sharp knife or a pair of pruning shears. Now you want to gently pull the baby away from the mother plant and you can repot the baby plant into a smaller pot in a well-draining soil mix.

Tip: Don’t start chopping away offsets (babies) as soon as they pop up. Wait till they’re at least 1″ (2.5 cm) before removing them from the mother plant. The bigger the baby, the more success you will have growing a new “Black Magic”!

Seeds

Since the Alocasia infernalis is a rare plant, buying legitimate seeds from a seller might be even rarer. If, however, you managed to get these seeds from somewhere the first thing you want to do when using them for propagation is soak them in distilled water overnight and sow in a well-draining potting soil (in the fall).

Sow the seeds 0.5″ (~1cm) in the soil. After that, water the seeds lightly and put a plastic bag over the containers to provide high humidity. Next, put the pot with the seeds (and plastic bag) in bright indirect sunlight and keep the soil moist.

In addition, you want to add a heat mat under the containers to keep the seedlings warm. The heat will improve the germination success rate.

After a couple of months, when the seedlings are 2″ (5cm) tall, carefully transplant them into bigger pots without damaging the roots.

Voila! You have now successfully propagated the Alocasia infernalis!