How to Grow and Care for All Types of Alocasia Macrorrhiza (Giant Taro)

Alocasia macrorrhiza is a common houseplant belonging to the Araceae family. Its care routine is similar to other tropical plants.

Alocasia macrorrhiza needs a strict watering schedule, lots of partial sunlight, and the occasional scoop of fertilizer. You’re essentially trying to mimic the Alocasia plant’s native rainforest environment to ensure it flourishes in your living space.

What Are Alocasia Macrorrhiza Plants?

Alocasia macrorrhiza, or giant taro plants are part of the Araceae family, native to regions like Maritime Southeast Asia, Queensland, and New Guinea. These evergreen perennials can survive fairly well in both indoor and outdoor conditions. 

The rhizomatous plants are nicknamed elephant ears because of their uncanny resemblance to the animal’s large, flappy, and irregularly shaped ears.

The plant’s leaves are prominently thick and are traced with vein-like midribs. The leaves stiffly jut out of their upright stems. Elephant ear plants can tower as high as three to six feet while spreading around two to four feet wide.

As for the leaves, they can stretch to about three to four feet. 

Overall, their large size will offer a rainforest-like appeal in your living space.

Quick Summary of Alocasia Macrorrhiza

• Scientific Name: Alocasia macrorrhiza
• Common Name: Giant elephant’s ear, giant taro, giant alocasia
• Light: Full sun or partial shade
• Watering: Medium to wet

• Temperature: 55 to 85℉
• Hardiness Zone: 9 to 12
• Soil pH: 5.7 to 6.3 or acid to neutral
• Soil Type: Mixture of soil, perlite, and peat moss
• Repotting: Every two years
• Pruning: Cut the dying leaves and lingering plant debris
• Size: 12 to 15 inches tall and 6 to 10 inches wide
• Bloom Time: Late spring to early summer
• Propagation: Stem cuttings from mature plants, basal offset division, or seed

How to Care for Alocasia Macrorrhiza

Alocasia macrorrhiza plants have similar care routines as many other houseplants since they primarily hail from a tropical climate. 

Here’s what you need to consider to keep your giant taro happy and healthy:

Provide Sunlight

Giant taro plants need sufficient sunlight to thrive. Think of the plant’s native environment. As a plant growing in the rainforest, it survived off of slivers of light entering through the dense forest roof.

For this reason, elephant ears tend to prefer partial sunlight, which makes them an ideal choice for an indoor plant. You can place them in a window facing south, north, or east for the best results.

You don’t want to expose your giant taro houseplant to excessive sunlight. More than two hours of it can leave scorch marks on your lush green leaves. Plus, you’ll notice the leaves wilting and curling.

Too little sunlight can stunt the houseplant’s growth. Signs of insufficient lighting can show from the large leaves’ discoloration as well.

Now, if your home doesn’t have ideal sunlight conditions for your elephant ear plant, you can resort to artificial lighting options. 

According to the Royal Horticultural Society, red light stimulates flowering, while blue light encourages general growth.

Mix Soil

A mixture of perlite, peat moss, and potting soil offers a suitable base for your giant taro houseplant. These components are well-draining and will keep the potting mix aerated.

Since elephant ear plants are particularly thirsty, you need to create a soil mix that will balance water retention and drainage.

Otherwise, if the plant holds too much water, it’ll face issues like root rot. Meanwhile, if the water drains too easily, your plant won’t thrive as well as it should.

In addition to drainage, you also have to consider the soil’s pH level. With a pH meter, you’ll want to ensure that it falls between 5.7 and 6.3. Subsequently, it should be an acidic to neutral potting mix.

Soil pH is critical to your giant taro’s survival. As per Iowa State University’s studies from the Department of Horticulture, a soil’s pH impacts the availability of nutrients in the plant.

Add Water

Giant taro houseplants flourish best in moist soil. The plant typically requires around 0.8 cups of water every nine days. This amount applies to an Alocasia macrorrhiza planted in a five-inch container or pot.

As a general rule, you can check if your giant taro needs a drink by tapping its topsoil. If it’s dry, pour in some water.

Seasons will heavily affect your watering schedule. During the winter, you won’t need to water your giant taro as much. Once March rolls around, you can gradually increase your houseplant’s water intake.

Plus, watering should also depend on the plant’s condition. Monitor its giant leaves and observe any changes, such as wilting, discoloration, shriveling, or drooping, and water accordingly.

Control Temperature

As a tropical perennial, Alocasia macrorrhiza plants indulge in warm temperatures. They grow best in temperatures ranging between 55 and 85℉. During winter time, when the temperature may fall under 50℉, your giant taro will struggle to grow.

If you want to maintain warmth, you can use a healing mat or insulating pot. Besides that, ensure that your plant isn’t exposed to fluctuating temperatures.

For instance, you don’t want to place it next to the AC or heater. Try to also keep it far from your door, which can bring in a cold draft. 

Additionally, when temperatures are low, you’ll want to avoid repotting your giant taro and cut back on the fertilizer and watering sessions.

If you keep your houseplant outside for summer and need to move it in, be cautious. The Johnson K State Research and Extension advises you to be wary of the many living organisms that could be attached to your plant, such as snails, slugs, and spiders.

Provide Fertilizer

While soil may provide essential nutrients to your giant taro, it can’t be its only source. So, your tropical houseplant will need fertilizer, especially during its growth seasons, summer, spring, and early fall. 

You’ll want to feed your giant taro fertilizer every two to four weeks during these seasons. The additional nutrients will keep the elephant ear plants’ stems and roots rigid while retaining your large leaves’ lush green shade.

You can use a fertilizer with an N-P-K or Nitrogen-Phosphorus-Potassium ratio of 3-1-2. Alternatively, you can administer a diluted houseplant fertilizer biweekly.

The Alocasia species will benefit from the nutrients, but over-fertilizing can lead to root burn, so be cautious with the portions.

How to Grow Alocasia Macrorrhiza Plants

You can grow giant Alocasia houseplants from ramets or seeds. Seeds will take a longer time to germinate. 

To get ramets, you’ll need to extract them from a mother plant that is around two to three years old. Ramets must be taken during the spring since it’s an active season for the houseplant. 

After acquiring your ramets or seeds, plant them in the recommended potting mix and water them regularly.

Make sure the seedling is provided with ample sunlight as well. As the plant grows, you’ll need to repot it to accommodate for the larger root size and avoid pot-bounding.

You can move it to a new, larger pot every year until it has matured. After that, repot every two to three years.

How to Repot Alocasia Macrorrhiza Plants

Before touching your Alocasia macrorrhiza houseplant for a repotting, make sure it’s spring when it’s at its fittest for recovery.

1. Prepare a pot one size larger than the previous one.
2. Add about three scoops of potting mix to it.
3. Remove the giant alocasia from its old pot, ensuring that it was watered a day before.
4. Take out the soil attached to the houseplant, exposing the root system.
5. Place the giant taro in its new pot.
6. Fill the remainder of the new pot with perlite, peat moss, and additional soil mix.
7. Shake it every few scoops to ensure the soil goes all the way down.
8. Press down around the stems for a compact finish.

How to Care for Alocasia Macrorrhiza in All Seasons

During its growing season, you can follow the standard care routine for your giant Alocasia. This means regular watering sessions, using fertilizer, and providing enough sunlight.

As for the wintertime, your houseplant will be dormant since there’s little sunlight and temperatures drop. Consequently, you won’t need to fertilize it. Instead, keep it indoors and warm. Plus, you’ll want to reduce the plant’s water intake.

How to Propagate Alocasia Macrorrhiza Plants

The best means to propagate plants like your elephant ear is through stem cuttings, basal division, and seeds. According to Missouri State University’s Plant Sciences & Technology department, basal division is the easiest method.

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To do so, uproot your giant taro plant and check for available tubers. Then, extract and plant them separately.

What Family Do Alocasia Macrorrhiza Plants Belong To?

The Alocasia macrorrhiza plant belongs to the Araceae family. 

Plants from that family have a unique inflorescence or a group of flowers arranged in a certain pattern on a stem. 

In the Alocasia’s case, its inflorescence is composed of a flower spadix or spathe, sheathed by bracts. Both are usually a mixture of white, yellow, and green.

Aside from that, every seed produced by an Arum family plant holds a single embryonic seed leaf. Their leaves are also distinctively reticule and hold calcium oxalate.

How Long Do Alocasia Macrorrhiza Plants Live For?

Not much is known about Alocasia macrorrhiza’s lifespan. While it can survive for several years, that primarily depends on environmental conditions. For instance, pests, disease, and improper care can take away years from the houseplant’s life. 

Other factors, like the plant’s propagation method, can also impact its lifespan. If you propagated your giant taro using a basal division, chances are it’ll inherit a similar life expectancy as its mother plant.

What Are Common Pest and Plant Diseases for Alocasia Macrorrhiza Plants?

Giant taro plants can be vulnerable to certain pests and diseases. In terms of pests, you’ll want to be wary of aphids, spider mites, and mealy bugs. 

These parasites have an appetite for your tropical houseplant. They typically suck on an Alocasia macrorrhiza’s sap, leaving lesions on the plant’s leaves.

You can deal with these infestations by wiping a cotton ball soaked in alcohol over the foliage. Alternatively, spraying the plant with soapy water and neem oil can also help.

Prevention involves quarantining new houseplants, in case of infection.

As for disease, elephant ear plants may develop root rot, leaf spot, botrytis, Xanthomonas, rust, and powdery mildew. Most symptoms of these diseases include leaf discoloration, lesions, and spotting.

Fungal-based diseases typically result from overwatering your plant or exposing it to an overly humid environment. In this case, you’ll want to repot your plant to control the infection and ensure you use sterilized potting soil.

How to Tell If Alocasia Macrorrhiza Plant Is Not Growing

You can tell your Alocasia plant isn’t growing from signs like droopy, spotty, or discolored leaves. These issues usually come from improper watering.

Not watering enough or overwatering your giant Alocasia can stunt its growth. On the other hand, your plant may be growing but appears leggy and weak. It’s usually a sign of low sun exposure.

Are Alocasia Macrorrhiza Plants Poisonous?

Alocasia macrorrhiza plants can be toxic to dogs, cats, and humans. It contains oxalic acid and asparagine protein compounds that can cause poisonous effects.

When ingested, you can experience vomiting, burning in your mouth and throat, swelling of the mouth and eyes, or diarrhea.

For this reason, you’ll want to keep your giant taro houseplant far from your children’s or pets’ reach.

How to Help Alocasia Macrorrhiza Plants Grow

Overall, keeping your Alocasia houseplant alive and thriving depends on lots of observation and care. You’ll want to watch for early signs of common problems, such as drooping leaves.

Floppy leaves are usually a sign of over or under-saturated potting soil. Subsequently, most of your attention should be on your giant taro’s watering schedule to ensure healthy growth.