Why Your Alocasia Dropped All Its Leaves

Why Your Alocasia Dropped All Its Leaves

I still remember the first time my Alocasia Polly lost every single leaf. I checked on it one morning, and it looked fine. Three weeks later, I had a pot of dirt with a sad little stem poking out. I thought I’d killed it. I felt like the worst plant parent on the planet.

Here’s the thing about Alocasias that nobody tells you when you buy one: they are dramatic. They will drop their leaves for reasons that seem completely random. Sometimes they go dormant. Sometimes they’re throwing a fit about spider mites. Sometimes you did everything right and they still look dead.

I’m going to walk you through the most common reasons your Alocasia decided to give up on life (or at least pretend to). More importantly, I’ll tell you how to figure out if your plant is actually dead or just being theatrical.

Is it dead or just dormant?

The first question you need to answer is whether your Alocasia is dead or dormant. This matters because your next steps are completely different.

Alocasias are tuberous plants. They grow from corms (which are like bulbs). In their natural habitat in Southeast Asia, they go through wet and dry seasons. During the dry season, they can drop all their leaves and survive underground until conditions improve. Your apartment is not Southeast Asia, but your plant doesn’t know that.

So how do you check? You need to look at the corm itself. I usually wait about two weeks after all the leaves have dropped before I do this. Gently dig around in the soil near the base of where the plant used to be. You’re looking for the corm, which feels like a small potato or a bulb.

If the corm is firm when you squeeze it gently, your plant is alive. It might be dormant, or it might be gathering energy to push out new growth. If the corm is mushy, slimy, or falls apart when you touch it, your plant is dead. There’s no coming back from a rotted corm.

I’ve had three Alocasias go dormant on me. Two came back after about six weeks. One never did, even though the corm stayed firm. Sometimes plants just decide they’re done, and that’s okay.

When an Alocasia goes dormant, you need to change your care routine. Cut back on watering significantly. I water mine maybe once every three weeks, just enough to keep the soil from turning into concrete. Don’t fertilize at all. Move the pot to a cooler spot if you can (around 60 to 65 degrees works well, according to the University of Florida’s IFAS Extension). Then you wait.

Some people dig up the corm and store it in barely damp peat moss until spring. I’ve never done this because I’m lazy and I don’t trust myself to remember where I put it. Leaving it in the pot has worked fine for me.

Dormancy is more common in fall and winter when light levels drop and indoor heating dries out the air. If your Alocasia drops its leaves in November, there’s a good chance it’s just taking a nap.

Spider mites love Alocasias

Now let’s talk about the worst possibility: spider mites. These tiny jerks absolutely love Alocasias. I don’t know what it is about these plants, but spider mites treat them like an all-you-can-eat buffet.

Spider mites are almost invisible to the naked eye. You usually don’t see the mites themselves. You see the damage first. The leaves start to look dull and dusty. Then you notice tiny yellow or brown spots, especially on the undersides. If you look really close (and I mean really close, or use your phone camera to zoom in), you might see fine webbing between the leaf and the stem.

By the time you notice all this, the infestation is usually pretty bad. Spider mites reproduce fast. One female can lay hundreds of eggs. They suck the sap out of the leaves, which causes them to yellow, brown, and eventually drop off.

I learned about spider mites the hard way with my Alocasia Zebrina. I thought the leaves were just aging out naturally. Then I noticed the webbing. I felt like I needed to burn down my whole plant shelf.

Here’s what you do if you catch spider mites: isolate the plant immediately. I mean right now, before you finish reading this sentence. Spider mites will spread to every plant in your collection if you let them.

Spray the entire plant down with water in your shower or sink. This physically removes a lot of the mites. Then you need to treat with something. I use insecticidal soap, which you can buy at any garden center or make yourself with a few drops of pure castile soap and water. Spray every single surface of every single leaf, top and bottom. Get the stems too. Do this every three days for at least two weeks.

Some people swear by neem oil. I’ve tried it and found it messy and not particularly effective, but your mileage may vary. Research from the University of California’s Agriculture and Natural Resources division suggests that insecticidal soaps and horticultural oils are generally more effective than neem for spider mites.

The real problem with spider mites is that they thrive in dry conditions. Indoor winter air is basically a spider mite paradise. If you can increase humidity around your Alocasia, you make life harder for the mites. I run a small humidifier near my plants from October through March. It’s not a cure, but it helps.

Above: A close up look at the symptoms.

Yellowing leaves and what they mean

Okay, so not every yellow leaf means your plant is dying. Alocasias are what people call “self-pruning.” They drop their oldest leaves as they grow new ones. This is completely normal.

The question is: which leaves are turning yellow?

If the oldest leaf (the one closest to the bottom, usually the smallest) turns yellow and dies while the plant is putting out new growth, that’s fine. That’s just the plant doing its thing. I usually get one yellow leaf every month or two on my healthy Alocasias.

If multiple leaves are turning yellow at once, or if the newest leaves are yellowing, you have a problem. Usually it’s a watering issue, but it could also be a fertilizer problem.

Overwatering causes yellow leaves. So does underwatering. I know that’s frustrating, but it’s true. The difference is in how the yellowing happens. Overwatering usually causes the leaves to turn yellow all over, often starting at the base. The stems might get soft and translucent. Underwatering causes yellowing that starts at the edges and works inward. The leaves feel papery and dry.

I killed my first Alocasia by overwatering. I watered it every week like clockwork because that’s what I’d read online. Turns out my apartment is cool and doesn’t get great light, so the soil stayed wet for way longer than a week. The roots rotted, the leaves yellowed, and that was that.

Now I water based on the soil, not the calendar. I stick my finger about two inches down into the pot. If it feels damp, I wait. If it feels dry, I water. My Alocasias get watered anywhere from every five days to every twelve days depending on the season and the weather.

Fertilizer can also cause yellowing if you overdo it. Alocasias are not heavy feeders. I fertilize mine maybe once a month during the growing season with a diluted liquid fertilizer (I use half the recommended strength). In fall and winter, I don’t fertilize at all.

Yellow leaves can also mean your plant needs more light. Alocasias want bright, indirect light. If yours is in a dark corner, it might be struggling to photosynthesize. The leaves will yellow and drop because the plant can’t support them.

Preventing root rot in bulbs

Let’s talk about root rot, because this is probably the number one killer of Alocasias in homes. These plants like moisture, but they absolutely cannot sit in waterlogged soil. The corms will rot, and once that happens, you’re usually done.

Root rot is caused by fungi and bacteria that thrive in wet, oxygen-poor conditions. When the soil stays soggy, the roots (and the corm) start to break down. You’ll notice the stems getting soft and mushy at the base. The leaves might yellow or wilt even though the soil is wet. If you pull the plant out, the roots are brown or black and smell terrible instead of being white or tan and firm.

The best way to prevent root rot is to get your soil mix right from the start. Alocasias need a chunky, well-draining mix. I don’t use straight potting soil. I make my own mix with about 40 percent potting soil, 30 percent perlite, 20 percent orchid bark, and 10 percent worm castings. Some people add coco coir or peat moss. The goal is a mix that holds some moisture but drains quickly.

Your pot matters too. It needs drainage holes. I don’t care how pretty that ceramic pot without holes is. Your Alocasia will die in it. I use plastic nursery pots and put them inside decorative pots if I want things to look nice.

Watering technique is the other piece. When you water, water thoroughly until water runs out the drainage holes. Then make sure you dump out any water that collects in the saucer or decorative pot. Never let your Alocasia sit in standing water.

If you catch root rot early, you might be able to save the plant. Take it out of the pot, rinse off all the old soil, and cut away any mushy or rotten roots and parts of the corm with clean scissors or a knife. Let it dry out for a day. Then repot in completely fresh, dry soil mix. Water very sparingly until you see new growth.

I tried this with an Alocasia Frydek that developed root rot last spring. I cut away about half the corm because it was mushy. I felt like I was performing surgery. I repotted it, crossed my fingers, and watered it maybe twice over the next month. It pushed out a new leaf about six weeks later. That plant is still alive today, although it’s smaller than it used to be.

Above: The tools you need to fix this.

Drooping stems after watering

This one confuses people. You water your Alocasia because the leaves are drooping, and then the drooping gets worse. What gives?

Drooping after watering usually means one of two things. Either you let the soil get way too dry and the plant went into shock when you watered it, or the roots are damaged and can’t take up water properly.

When soil gets bone dry, it can become hydrophobic. That means water runs right through it instead of being absorbed. You water the plant, the water goes straight out the drainage holes, and the root ball stays dry. The plant droops even more because it didn’t actually get any water.

I’ve done this more times than I’d like to admit. The fix is to water more slowly, or to bottom water. For bottom watering, I put the whole pot in a basin of water and let it sit for 20 to 30 minutes. The soil absorbs water from the bottom up. You can actually feel the pot get heavier as it soaks up water. Then I let it drain completely before putting it back in its spot.

The other possibility is root damage. If the roots are rotted or damaged, they can’t absorb water even when it’s available. The plant droops because it’s essentially dying of thirst even though there’s water in the soil. This is harder to fix. You’d need to check the roots and potentially cut away damaged portions like I described in the previous section.

Sometimes drooping happens because of temperature shock. If you water with very cold water, it can shock the roots. I learned this from a publication by the University of Georgia Cooperative Extension. Now I use room temperature water for all my plants. I fill my watering can and let it sit overnight before I use it.

Drooping can also happen if you move your Alocasia to a brighter spot. The plant suddenly needs more water because it’s photosynthesizing more, but the roots haven’t adjusted yet. Give it a week or two. If the plant is otherwise healthy, it will adapt.

One last thing about drooping: Alocasias are prayer plants’ dramatic cousins. Their leaves naturally angle themselves toward light and may droop slightly at night. If your plant perks up in the morning, it’s probably fine. If it’s drooping all the time and getting worse, then you have a problem.

The truth is, Alocasias are not easy plants. They have specific needs, and they will punish you if you don’t meet them. But they’re also resilient in weird ways. I’ve had plants lose every leaf and come back from a corm that I thought was dead. I’ve also had plants that looked perfect one day and collapsed the next.

If your Alocasia dropped all its leaves, take a breath. Check the corm. Look for pests. Evaluate your watering and soil. Then adjust and wait. Plants work on their own timeline, not ours.

References

University of Florida IFAS Extension. “Alocasia, Caladium, and Xanthosoma.” Environmental Horticulture Department.

University of California Agriculture and Natural Resources. “Spider Mites Management Guidelines.” UC IPM Pest Management Guidelines.

University of Georgia Cooperative Extension. “Indoor Plant Care: Watering.” College of Agricultural and Environmental Sciences.