How to Care for and Grow Alocasia ‘Sumo’ (Elephant Ear)

If you are into Alocasia plants and you also like plants that can grow really big leaves, the Alocasia ‘Sumo’ (also known as the Elephant Ear) is definitely a plant you want to check out.

The Alocasia ‘Sumo’ is a hybrid between the Alocasia ‘Portora’ and Alocasia princess ‘Purple Cloak’. It has the size of a ‘Portora’ and the thinner, colorful, and pointed leaves of a ‘Purple Cloak’.

Ultimately, this plant can grow up to 10 feet (3 m) tall with leaves up to 4′ (1.2 m) long and 2.5′ (75 cm) wide, which makes this Alocasia great for a tropical garden or a big living room.

The Alocasia ‘Sumo’ thrives best in bright indirect sunlight, a well-draining soil mix, temperatures between 65 and 75ºF (18 and 24ºC), and preferably higher humidity levels (at least 70%) but normal room humidity will also do. It only needs to be watered when to top 2 inches of the soil are dry.

In this care guide, I will go over everything from A to Z so you can fully understand this plant. I will discuss topics including how to water the plant, the best soil to use, what fertilizer to use, what environment it likes, and how to propagate the plant.

Images by Edi from TropicalplantsFL.

Summary:

  • Light: Bright indirect sunlight
  • Water: Only water when the top 2 inches of the soil are dry
  • Soil: Well-draining soil mix
  • Fertilizer: Every other month (during the growing season)
  • Size: Grows up to 10′ (3 m) tall
  • Size: Leaves grow up to 4′ (1.2 m) long and 2.5′ (75 cm) wide
  • Temperature: Between 65 and 75ºF (18 and 24ºC)
  • Humidity: Preferable above 60%
  • Cold hardy: Not cold hardy
  • Zone: 8-11
  • Propagation: By division and offsets
  • Toxicity: Toxic to humans and animals

General Care for Alocasia ‘Sumo’ (Elephant Ear)

Alocasia plants are usually easy to care for and very rewarding when it comes to indoor tropical plants. The same goes for the Alocasia ‘Sumo’, which actually has similar needs as other Alocasia plants.

Water

The amount of water the ‘Elephant Ear’ Alocasia needs depends on the temperature that it is staying in and the amount of sunlight it receives. Higher temperatures and more sun will make the Alocasia thirstier. For example, during the hot summer months, the plant needs more water than during the colder winter months.

This plant wants its soil damp but not saturated with water and likes to slightly dry out in between waterings. You don’t want to keep the soil too wet because this will cause the roots to rot which can kill the plant.

Knowing when to water the Elephant Ear can be quite hard because it (unfortunately) won’t tell you when it’s thirsty. An easy and successful method that I use to find out when it’s time to water my Alocasia is to feel the top layer of the soil. If the top 2 inches (5 cm) of the soil are dry, then it’s time to water again.

When watering this plant, water it until water starts to drip out of the drainage holes.

Another great way to know exactly when and how much to water your Alocasia ‘Sumo’ is by using a moisture probe. This probe will indicate how much moisture the soil contains. For Alocasia plants, 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.

Light

The Alocasia ‘Sumo’ will grow best in medium to bright indirect sunlight but can also tolerate a couple of hours of morning sun or dappled direct sunlight. However, avoid too much direct sunlight because this will burn the leaves and make them crispy brown.

For bright indirect sunlight, place the plant besides an east-facing window, or in the middle of a room that receives full light from a south- or west-facing window.

If you only have a south-facing window with lots of direct sunlight, keeping the plant behind curtains when the sun is out will prevent any sun damage from occurring.

On the other hand, if you want to place this plant in a dark office or a room with low light conditions, I have to disappoint you. The Alocasia ‘Sumo’ doesn’t like low light and will suffer in this condition.

Soil

When it comes to soil, the Alocasia ‘Sumo’ requires a loamy, rich, and organic soil mix. This soil mix needs to be well-draining, moist-retentive, and slightly acidic to neutral pH.

Because there are so many different soil brands on the market, choosing the right soil mix for your plant can be quite difficult. To keep things easy and effective, you can either make a soil mix yourself or buy a pre-made one.

You can make a proper soil mix with one part soil, one part perlite or coarse potting sand, and one part orchid bark.

If you want to buy a good pre-made soil mix, I would suggest you buy a high-quality aroid mix.

The only downside of buying a pre-made soil mix is that you don’t exactly know what is in it and it could be a bad soil mix. A pre-made soil mix that retains too much water is not good because too much water will cause the roots of the plant to rot. But, don’t worry because you can always add perlite to the soil which will allow it to drain more easily.

Repotting

The Elephant Ear ‘Sumo’ is a relatively fast grower and likes to be slightly rootbound. Despite the fast growth of this plant, it only needs to be repotted once the plant has filled out the pot (which is usually once every 2 years).

If you’re not sure when you need to repot this plant, pick the plant up (good workout as well) and look at the bottom of the pot. If you can see the roots of the plant through the drainage holes, it’s time to repot the plant!

The best time of the year to repot this plant is in the early spring, before the start of the growing season.

Repotting this plant is really simple, here are 5 steps:

  1. Choose a pot that is one size (2 inches) bigger
  2. Put in a layer of well-draining soil in the new pot
  3. Take the plant out of its old pot
  4. Put the plant in the new (bigger) pot
  5. Fill the empty spaces of the new pot with a well-draining soil mix

Remember to always use a pot that has drainage holes, so the excess water can drain out of the pot. Otherwise, the soil will stay too wet and cause problems with root rot.

Fertilizer

The Alocasia ‘Sumo’ is a heavy feeder and fertilizing this plant frequently is the only way to keep up with its appetite. Because it can grow up to 10′ tall (3 m), it will rather quickly use the nutrients from the soil to grow.

Applying fertilizer should only be done in the growing season (spring and summer) because during this time the plant uses a lot of nutrients to grow. I would recommend fertilizing this plant every month (only in spring and summer) with a diluted balanced fertilizer (like a 10-10-10).

You can also check out my shop where I have listed a great organic fertilizer (worm castings).

I always dilute the fertilizer to 1/2 or 1/4 strength to make sure I don’t overfertilize my plants. With the Alocasia ‘Sumo,’ you can also start with a diluted fertilizer and you can always increase the amount if you are not happy with the results.

However, you don’t want to overfertilize it because an excess of minerals in the soil will burn the leaves.

Humidity

The Elephant Ear is a tropical plant that thrives best in slightly higher humidity levels (60%+) but will also tolerate normal humidity levels (30-50%).

Depending on where you live and how humid the air is, you might want to increase the humidity artificially.

Here are 3 easy ways you can increase the humidity around the plant:

  • Use a humidifier
  • Mist the plant (2 times a week)
  • Place the plant in a humid room (bathroom or kitchen) but make sure it gets enough light

Cold air can’t hold nearly as much moisture as warm air. This means that during the winter months the air is much drier than during the summer.

During the winter you want to keep an eye on this plant during the winter months. If the humidity is too low, the leaves turn crunchy with a brown outline. When this happens, you want to use one of the methods listed above to increase the humidity.

Temperature

The ideal temperature range for this plant is between 65 and 75ºF (18 and 24ºC) and grows at its best when the temperature is around 70ºF (21ºC). This makes ‘Sumo’ Alocasia perfect to keep indoors.

However, you can also grow it outdoors if you want. It is winter hardy in USDA plant hardiness zones 8-11.

It is a warm grower, which means it likes the warmer temperatures throughout the whole year.

One thing that this plant really doesn’t like is cold temperatures. Especially cold drafts, which can cause the plant a lot of stress.

Cold drafts can cause things like drooping or wilting, discoloration of the leaves, and can even cause the plant to die.

If you notice that your plant is having a hard time growing or it is experiencing one or more of the aforementioned signs, make sure you eliminate any cold drafts.

Pruning

Pruning this plant is not necessary, however, there might be a couple of reasons why you want to prune this plant once in a while.

For example, once your Alocasia Elephant Ear has grown too big and is all over the place, you can choose to prune it to make it appear fuller and compact.

Also trimming off any old or damaged leaves won’t hurt the plant and will keep it looking fresh.

If you want to prune it, use clean pruning shears or a sharp knife and cut the stem close to the base of the plant. Make a clean cut and try not to tear or rip the stem apart.

Light pruning can be done throughout the whole year, and trimming off large parts of the plant can best be done in the early spring (beginning of the growing season).

Pests & Diseases

Generally, the Alocasia ‘Sumo’ is not susceptible to any pests but can suffer from root rot and bacteria diseases if overwatered.

Keeping a proper watering schedule and only watering the plant when the top 2 inches of the soil are dry is very important to avoid these problems.

One way to eliminate pests and diseases that I found out to work really well is to use a water/peroxide solution. Especially if your Alocasia ‘Sumo’ is suffering from root rot. Watering the plant once with this solution should eliminate the root rot disease.

To make this solution, mix one-part of additive-free 3% hydrogen peroxide with ten parts water. Water the plant thoroughly and then allow the top 3 inches of the soil to dry out completely. Be careful not to repeat this too often because this will hurt the plant.

If you like rare house plants that are easy to care for, check out the Alocasia maharani (Grey Dragon)

Alocasia 'Sumo' plant in pot

How to Propagate Alocasia ‘Sumo’ (Elephant Ear)

Propagating the Elephant Ear ‘Sumo’ can easily be done by either division or offsets.

For the best success rate of propagation, you want to propagate in the growing seasons (spring and summer). During this time, the roots will grow quickly and the plant will establish faster after propagation.

Division

The easiest and most successful way to propagate the “Sumo” is by division.

  • First, you want to take the plant out of its pot and carefully remove the soil around the roots.
  • Then, split the rhizome using a sharp knife. Be sure that there are the same amount of roots on both parts.
  • Next, use a well-draining soil mix and plant the divided plant in a pot with drainage holes.

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

Offsets

The Alocasia ‘Sumo’ 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.

Tip: Don’t start cutting away offsets (babies) as soon as they pop up. Wait till they’re at least 3″ (7.5 cm) tall before removing them from the mother plant. The bigger the baby, the more success you will have growing a new Alocasia ‘Sumo’!

Good luck!

Seeds

*As the Alocasia ‘Sumo’ matures, it can grow seed pods, however, planting these seeds and growing new plants from them can be a very long process.

Because I’ve never grown Alocasia ‘Sumo’ seeds, I don’t know if it’s even possible to do that. I have read from various sources that it’s not possible to propagate this plant from seeds because the flowers are sterile, or the plant will not come true from seeds.

It’s faster and easier to propagate this plant from division or offsets.

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Related questions:

Why is my Alocasia ‘Sumo’ dripping water?

If your Alocasia ‘Sumo’ is dripping water from its leaves, it means it’s slightly overwatered and it’s trying to get rid of excess water.

The plant will “sweat” from the tiny pores that are on its leaves.

If you see that your plant is dripping water from its leaves, just make sure that you are not overwatering the plant again. Only water the plant when the top 2 inches of the soil are dry.

Why are the leaves of my Alocasia ‘Sumo’ turning yellow?

If your Alocasia ‘Sumo’ has yellow leaves, it’s probably an indication that the soil has been too wet or too dry. To prevent the leaves from turning yellow, only water the plant when the top 2 inches (5 cm) of the soil are dry. You can also use a moisture probe and water when the probe indicates between 2 and 3.

Why are the leaves of my Alocasia ‘Sumo’ turning brown?

The leaves will turn brown because of low humidity, too much fertilizer, too much or too little sunlight, or other factors that give the plant stress (like a pest or root rot disease).

You can stop the leaves from turning brown by fixing the roots of the problem. Either increasing the humidity, removing excess minerals by flushing the soil, giving the plant only bright indirect sunlight, and removing any infested pests.

Increasing humidity can be done by misting the plant twice a week (with a spray bottle with water) and also when using a fertilizer, always make sure you dilute it to about 1/4 of its strength to play safe.

By following the care instructions presented in this care guide, you can possibly prevent brown leaves!

Why is my Alocasia ‘Sumo’ drooping?

Drooping leaves are often the effect of underwatering the Elephant Ear. If water is not provided for longer periods of time, the water balance within the plant can get thrown off. This will cause the cells in the stems to lose their strength and start drooping.

The Alocasia ‘Sumo’ likes to have damp soil that is not waterlogged. Only water this plant when the top 2 inches of the soil are dry. Put your fingers in the soil of the plant to feel if the soil is dry or not.

Why is my Alocasia ‘Sumo’ dropping leaves?

The most common reason why your Alocasia ‘Sumo’ is dropping its leaves is because of under or overwatering. However, the plant can also drop its leaves when it’s infected by a pest, gets too little light, or if the humidity is too low.

By keeping a tight watering schedule alone, you can often prevent the plant from dropping its leaves. If this is not working, you have to find the roots of the problem. By following the steps in this care guide, you can eliminate these problems.

Is the Alocasia ‘Sumo’ toxic to pets?

All parts of this plant contain calcium oxalate crystals, which will irritate the mouth and esophagus if eaten. This makes the Alocasia ‘Sumo’ toxic to pets like cats, dogs, rabbits, and birds.

Complications that can arise after ingesting parts of the plant are excessive drooling, swelling of the mouth and esophagus, coughing, and throwing up.

If one or more of the above symptoms occurs, call the vets to make sure your pets are okay.

Can you grow the Alocasia ‘Sumo’ in sphagnum peat moss?

Sphagnum peat moss is great for drainage and is very rich in organic nutrients. Mixing a little bit of peat moss into your premade soil mix can benefit the plant, however, planting your Alocasia ‘Sumo’ in pure sphagnum peat moss might not be a good idea.

Sphagnum peat moss is a very light medium and with a fast-growing and big plant like the Alocasia ‘Sumo’, the plant will probably fall over when it gets too big.

For proper growth, the Elephant Ear plant needs a well-aerated, well-draining, nutrient-rich soil mix that also can hold water.

Every growing medium has its own benefit and challenge. In general Elephant Ear plants like soil that contains a mixture of different mediums.

Can you propagate Alocasia ‘Sumo’ from a leaf or stem cutting?

Unfortunately, the Alocasia ‘Sumo’ can neither be propagated from a leaf or stem cutting. It can only be propagated by dividing the rhizomes of the plant or by offsets, which are actually baby versions of the plant that are identical to the mother plant.

An offset can randomly grow next to the mother plant throughout the whole year

Conclusion

The Alocasia ‘Sumo’ is a strong plant that is not susceptible to pests and is generally easy to grow as an indoor or outdoor plant.

I hope you learned something from this care guide. If you did learn something, please share this guide on social media, that would really help my blog out!

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