Black Stemmed Alocasia Care & Growing Guide (Alocasia Macrorrhiza Black Stem)

Last Updated on March 19, 2022 by Admin

The Black Stemmed Alocasia is also called the Alocasia Black Stem or the Elephant Ears Black Stem. To be more specific, it refers to the Alocasia Macrorrhiza Black Stem.

This is a stunning plant with large green heart shaped leaves that face more upright and droop down. But its most distinctive feature are its black stems which is uncommon in Alocasia varieties.

This plant is rare because of this feature. It is also unusual because of this.

However, it is important to understand that the Black Stemmed Alocasia is a healthy plant whose thick, upright, rigid stems happen to be black in color.

It is different from root or stem rot which causes your plant stem to turn black. Any plant experience this will not only have mushy, soft black stems but it will also stink.

So, I just wanted to note the difference.

How do your care for the Black Stemmed Alocasia? The plant prefers bright, indirect light and well-drained, moist soil. Avoid getting the soil wet or soggy. It will benefit from fertilizer when it is actively growing in the warmer months. For optimal growth give it humidity of 60% to 70% and leave it in a warm environment.

Table of Contents

Black Stemmed Alocasia Plant Care

Alocasia Black Stem Light Requirements

The Black Stemmed Alocasia thrives on medium to bright indirect light. This will allow it to grow faster. Sufficient lighting is also crucial for the plant to produce its huge, impressive leaves.

That said, it can tolerate low light as well.

This makes it an easy plant to grow indoors. Although if possible try to keep it near an east facing window. This will give it the morning light it enjoys.

On the other hand, you want to be more careful with afternoon light, especially direct sunlight. That’s because the plant cannot tolerate very intense light.

This is due to its natural habitat.

The plant comes from the tropical and subtropical forests of Asia where it lives under the canopy of the large trees. So, while it can grow up to 15 feet tall or a little more, it is relatively small compared to the much bigger trees in the jungle.

As such, the sun’s rays are blocked by the leaves and branches overhead.

For this reason the Alocasia Black Stem is used to indirect, dappled or filtered light. Thus, this is the best kind of light to give it for optimal growth.

Outdoors, keep the plant in a partial shade area away from full sun.

Alocasia Black Stem Temperature

The Black Stemmed Alocasia prefers temperatures between 65 to 80 degrees Fahrenheit. Again, this comes from its native environment.

In the parts of Asia where the plant grows, the weather is hot and humid all year round because they are near the equator.

For this reason, the Alocasia Black Stem enjoys moderate to warm climate that is consistent. It also won’t mind if temperatures go up to 90 or 95 degrees Fahrenheit.

However, it is not cold hardy.

The Alocasia Macrorrhiza Black Stem will struggle with temperatures under 60 degrees Fahrenheit.

So, it is a good idea to keep it away from the colder rooms in your home including those with air conditioning or cold drafts coming from open windows.

Outdoors, don’t forget to bring the plant back inside if you take it outdoors for the summer. It won’t survive the winter as the plant will die back to the soil.

However, its underground structure will still be healthy. So, come spring it will start growing again. But it has to start from the beginning again since it lost the entire plant and all the leaves.

That said, the Alocasia Macrorrhiza Black Stem enjoys USDA Hardiness Zones 9 to 11, which has warm temperature all year round with no snow. Therefore, if you live in these parts, you can keep the plant outdoors 365 days a year without having to worry about the cold.

Humidity

The Black Stemmed Alocasia likes high humidity, ideally at 60% and higher. Although it can tolerate as 50% and a bit lower than that without harm.

Good humidity is important for the plant if you want it to grow fast and produce large foliage.

However, be aware that most homes have average humidity running between 20% to 50%, which may be a bit of an issue depending on where you live.

If you need to increase humidity to keep the plant happy, you can invest in a humidifier.

But there are free ways you can try as well.

I like to set up a humidity tray which is just a tray with pebbles on it. Then fill the tray with water until it reaches halfway or so of the pebbles. Place the plant above the pebbles so the pot does not touch the water.

As the water evaporates, it increases humidity around the plant.

This is free and low maintenance since you only need to replenish the water when it gets depleted.

Alternatively, you can mist the plant or move it to the bathroom. Giving it a shower every few weeks also works.

Related

How Often to Water Black Stemmed Alocasia

The Black Stemmed Alocasia likes to drink. As such, it prefers soil to stay consistently moist. However, you need to be careful while doing this since the plant can be susceptible to overwatering.

Thus, be mindful of how much and how often you water this alocasia.

Too much moisture can eventually lead to root rot as the roots end up drowning in water. This can easily happen if you add water while the soil is still wet or moist.

That’s because if the surface of the soil is moist or wet, the middle and bottom will have more moisture. So, adding liquid at this time can cause the roots to suffocate due to too much water.

This is when root rot comes in.

Therefore, the best way to water the plant is to wait until the top 2 inches of soil has dried completely. You can also wait until the top quarter (25%) of soil is dry between waterings.

This second method is more conservative, but it also reduces the risk of overwatering further. Plus, it works better if you have a busy schedule since you don’t have to water as often.

Because the weather changes, you can expect your watering schedule to vary based on the time of year.

Thus, I don’t suggest in following a fixed watering schedule.

During the summer when the weather is hot, the soil will dry faster. On the other hand, it takes longer for soil to dry during winters.

By following the methods above, you allow the soil to tell you when the plant needs watering.

In hot weather it dries faster so you’ll be watering more frequently. In winter, you’ll automatically scale back as the soil stays moist longer.

Alocasia Black Stem Potting Soil

Elephant Ears Black Stem need porous, well-draining soil that stays moist. I know that this sounds contradictory. However, with potting soil it makes a lot of sense.

This kind of soil holds moisture to keep the roots hydrated. But at the same time, it quickly drains excess moisture to prevent overwatering and waterlogged soil.

The porous nature of the soil allows the roots to get the oxygen they need to stay healthy.

These features are all important for the Alocasia Black Stem because its roots don’t like drying out nor can they tolerate sitting in water for long periods of time.

And you can achieve this by combining 3 ingredients. Just put equal parts of:

Potting soil
Peat
Perlite

The potting soil and peat retain moisture and provide organic matter. Meanwhile the perlite keeps the soil light and increases drainage. This way the plant gets enough oxygen to its roots.

Besides using the right soil, make sure the pot you choose to put the plant is had drainage holes.

This will let excess liquid that drains from the soil drip out of the pot instead of just pooling at the bottom of the container keeping the soil wet.

Thus, in addition to knowing when to water, using the right kind of potting mix for your Black Stemmed Alocasia, is important in preventing overwatering and waterlogged soil.

Doing so lets you avoid root rot.

Fertilizer

The Black Stemmed Alocasia needs fertilizer if you want it to grow optimally. In fact, it is a heavy feeder so the nutrients will benefit it.

Giving it the right fertilizer and amount will allow it to grow fast and produce large foliage.

However, don’t try to feed it more than needed. Some growers do this because they see the plant is a big feeder.

Over fertilizer can cause serious issues. One of these is root damage due to fertilizer burn.

This will affect your plant’s ability to absorb nutrients and water from the soil. As such, it will ultimately affect it growth as well.

Therefore, make sure to following the instructions on the label.

If you go the traditional route, you can use a balanced, liquid houseplant fertilizer. An N-P-K of 15-15-15 or 20-20-20 works well for this plant.

Feed it once a month during its growing season (spring and summer). And stop feeding come fall as the weather cools down. Don’t fertilize the Alocasia Black Stem during winter as it won’t grow much then.

Doing so only increases the risk of fertilizer burn as you add more salt into the soil.

You can likewise go with slow release fertilizer which is a safer option if you want to avoid overfeeding.

This fertilizer will release the nutrients over time. So, the amount of salt that is released is also gradual.

To make sure that too much salt does not build up, flush the soil using water once every few months. This will remove the excess minerals and salts from the potting mix.

Alocasia Black Stem Pruning

The Black Stemmed Alocasia can grow to between 12 to 15 feet upon maturity. Its size will be limited when kept indoors. Nevertheless, you will need to prune it if you want to keep it as a houseplant.

Pruning will allow you to keep the plant between 6 to 8 feet tall indoors. Although, I’ve seen some growers whose Alocasia Macrorrhiza Black Stem are only about 4 to 5 feet which makes them great for living rooms or even hallways inside your home.

This is an amazing plant to have indoors because of its black stems and huge leaves. You want to keep it in an equally good sized pot or planter to make it impressive.

Because it does not produce a ton of leaves and each leaf will get huge in size, pruning has to be done judiciously. On the one hand, you want to limit its size. But you also don’t want to make it too sparse.

Therefore, another option some growers take is to prune the roots instead.

They do so once the plant reaches the size they more or less want it to stop.

Instead of repotting to a larger container when the Alocasia Macrorrhiza Black Stem gets root bound, the prune the roots so it can fit back to the same pot.

In doing so, the Black Stemmed Alocasia maintains its size and large leaves.

How to Propagate Black Stemmed Alocasia

The most common ways of propagating the Black Stemmed Alocasia are:

Division
From offsets

Propagating by Division is the best and most effective way to propagate the Alocasia Black Stem. And you’ll be dividing the rhizomes and plant them into their own containers.

These will grow into large, mature plants that look like their parent in time.

Here’s how to propagate Black Stemmed Alocasia by division.

Take the plant out of its container. For larger plants, tip it to its side and slide it out the pot.
Remove excess soil as you need to see the roots to divide the plant.
Decide how many divisions and where you want to cut the clumps. Make sure each section you separate will have its own set of roots, stems and leaves. This way you get a new plant that already has leaves and can sustain itself.
Use a sterile knife to cut the rhizomes into the sections you want. You can make 2 or more divisions depending on how many new plants you wish to get form the parent.
Pot each of the smaller divisions in well-draining soil.

Propagating from Offsets is the simplest way to produce new Black Stemmed Alocasia plants. However, it is not predictable since you don’t know when the plant will produce offsets. It can do so any time of the year. But it may also wait a couple of years before doing so.

Thus, while easy to do, it is not reliable.

In any case, here’s how to propagate the Alocasia Black Stem by using its offsets.

Check the base of the plants to see if there are any offsets or pups that have grown. If there are, take note of how many and big they currently are.
You only want to take those that are at least 3 inches long. Avoid the smaller ones as they’re less likely to survive on their own at the moment. Allow them to grow a bit more.
Take a sterile knife and cut the roots of the offsets that attach it to the parent plant.
Offsets are small/young versions of the plant. therefore, you can plant the offsets and whey will grow into clones of their parent.

How to Repot or Transplant Black Stemmed Alocasia

The Black Stemmed Alocasia will develop a well-established root system. As such, it will need a large pot as it grows. This will provide the tall plant with large leaves sufficient support and foundation down below.

As such, be ready to use larger containers over time.

That said, repotting is only needed every 2 years on average.

This is when the plant gets root bound. Don’t repot the plant unnecessarily as this will negatively impact its growth.

On the other hand, if you want to stop the plant from growing or it has reached the size you want, you can prune its roots once it gets root bound.

Doing so allows you to return the plant to its current pot. Although, I suggest refreshing the soil first.

This way, it maintains its health, looks and size.

Is It Toxic/Poisonous to Humans, Cats & Dogs

Yes, the Black Stemmed Alocasia is toxic. Therefore, avoid letting young children, dogs or cats ingest any part of the plant.

Because the plant will get big and tall, its leaves are less of an issue as young kids and pets won’t likely reach them once the plant gets bigger.

However, all parts of the plant is toxic. So, it is still a good idea to keep it out of their reach.

Black Stemmed Alocasia Problems & Troubleshooting

Pests

Spider mites, mealybugs, aphids and scale are the most common pests to attack the Black Stemmed Alocasia. These are sap suckers, which means they feed on the plant’s internal juices.

While they are not harmful when only a few are present, these bugs tend to grow very rapidly in number.

Therefore, you want to catch them and eradicate them as early as possible.

The only way to do that is regular inspection. And if you find any, treat with neem oil or insecticidal soap.

Diseases

Root rot is the #1 thing to watch out for. It is caused by excess moisture and can eventually destroy your plant.

Overwatering and waterlogged soil are the main culprits.

Therefore, always check the soil before you add water. And wait until the top of the soil is dry before you add more water.

Also use well-draining soil to ensure that excess liquid is drained. This way the roots don’t end up sitting in water for long periods of time.

Finally, use a pot with drainage holes so the excess water can exit.