Why Your Rubber Plant is Dropping Leaves

Why Your Rubber Plant is Dropping Leaves

I walked into my living room last Tuesday and found three yellow leaves on the floor next to my Rubber Plant. My first thought was panic. My second thought was to open Google and fall down a rabbit hole of conflicting advice. So I spent the next few days reading research papers, asking my plant-nerd friends, and checking what actual horticulturists say about Ficus elastica.

Here’s what I learned. Some leaf drop is normal. Some is a cry for help. The trick is knowing which is which.

Why the bottom leaves turn yellow and fall

Let me start with the good news. If your Rubber Plant is losing one or two lower leaves every few months, that’s just what mature plants do. They shed their oldest leaves to focus energy on new growth. I didn’t know this when I first got into plants, and I nearly killed my first Rubber Plant by overwatering it in a desperate attempt to “fix” perfectly normal behavior.

The lower leaves on a Rubber Plant are the oldest ones. As the plant grows taller and produces new leaves at the top, it eventually decides the bottom leaves aren’t worth the energy anymore. They turn yellow, then brown, and fall off. This is especially common if your plant is in lower light, because it has less energy to maintain all its foliage.

You can tell this is natural shedding if the leaf turns completely yellow before dropping, if it happens slowly over a week or two, and if the rest of the plant looks healthy. The new growth at the top should be firm and green. If that’s the case, just remove the yellow leaf once it’s ready to fall and move on with your life.

But here’s where it gets tricky. Sometimes the bottom leaves yellow because of stress, not age. If you’re losing more than a couple leaves per month, or if the yellowing is happening fast, something else is going on. Usually it’s a watering issue, but it could also be a sudden temperature drop or a dramatic change in light.

According to the University of Florida’s IFAS Extension, Ficus elastica is pretty forgiving, but it doesn’t like rapid changes in its environment. When I moved my plant from a bright corner to a darker hallway, it dropped four leaves in two weeks. I moved it back, and the dropping stopped. Plants don’t read the room. They just react.

Signs of overwatering in Ficus

Overwatering is the number one killer of houseplants, and Rubber Plants are no exception. I know this because I’ve done it. Twice.

The confusing part is that overwatering doesn’t mean you’re watering too often in the way you’d think. It means the roots are sitting in soggy soil for too long, which cuts off their oxygen supply. The roots start to rot, and the plant can’t absorb water properly. Ironically, an overwatered plant often looks like it’s thirsty.

Here’s what overwatering looks like on a Rubber Plant. The leaves turn yellow, but not in the slow, graceful way that natural shedding happens. They yellow fast, sometimes within a few days. The yellow often starts at the edges or between the veins. You might also see brown spots or a general droopiness. If you check the soil, it’s wet or at least damp, even though you watered a week ago.

The real test is the roots. If you’re brave enough to unpot the plant, healthy roots are white or light tan and firm. Rotting roots are brown, black, or gray, and they feel mushy. Sometimes they smell bad. I once pulled a plant out of its pot and the roots literally fell apart in my hands. That plant did not make it.

If you catch it early, you can fix overwatering. Stop watering immediately. Let the soil dry out almost completely before you water again. If the roots are already rotting, you’ll need to unpot the plant, trim away the dead roots with clean scissors, and repot it in fresh, well-draining soil. I use a mix of regular potting soil with added perlite because pure potting soil holds too much moisture for my taste.

The best way to avoid overwatering is to check the soil before you water. Stick your finger into the soil up to your second knuckle. If it feels damp, wait. Rubber Plants can handle a bit of dryness better than they can handle soggy roots. I water mine about once every week to ten days in the summer, and once every two weeks in the winter when it’s cooler and the plant isn’t growing much.

Also, make sure your pot has drainage holes. I don’t care how pretty that ceramic pot is. If water can’t escape, your plant will eventually drown.

Above: A close up look at the symptoms.

Curling leaves and what they mean

Curled leaves on a Rubber Plant usually mean one of two things. Either the plant is too dry, or it’s stressed by something in its environment.

When a Rubber Plant doesn’t get enough water, it curls its leaves inward to reduce the surface area exposed to air. This helps it conserve moisture. The leaves might also feel a bit thinner or less firm than usual. If you see this, check the soil. If it’s bone dry and the pot feels light when you pick it up, your plant is thirsty.

I underwater my plants more often than I overwater them now, because I got paranoid after killing a few with too much water. My Rubber Plant has definitely told me off a few times by curling its leaves tight. I water it thoroughly, and within a day or two, the leaves relax again.

But curling can also happen when the plant is uncomfortable for other reasons. Low humidity is a big one. Rubber Plants come from Southeast Asia, where the air is humid. Most of our homes, especially in winter, are dry as a bone. According to research from the American Society for Horticultural Science, Ficus species prefer humidity levels around 50 to 60 percent, but they can tolerate lower levels if they’re otherwise healthy.

I don’t run a humidifier for my Rubber Plant because honestly, I don’t have the patience for that. But I do keep it away from heating vents, and I group it with other plants so they create a little microclimate together. Some people mist their plants, but that’s mostly for show. It doesn’t actually raise humidity in any meaningful way.

Another cause of curling is temperature stress. If your plant is near a drafty window in winter or directly under an air conditioning vent in summer, the leaves might curl in protest. Rubber Plants like stable temperatures between 60 and 75 degrees Fahrenheit. They can handle a bit outside that range, but they won’t be happy about it.

Handling the sticky white sap safely

If you’ve ever pruned a Rubber Plant or accidentally broken a leaf, you’ve seen the sap. It’s white, sticky, and it gets everywhere. This is latex, the same stuff used to make natural rubber. It’s also a skin irritant for a lot of people.

I learned this the hard way when I pruned my Rubber Plant without gloves. Within an hour, my hands were itchy and red. Some people have more severe reactions, especially if they have a latex allergy. The sap can also irritate your eyes if you touch them after handling the plant.

Here’s how I deal with it now. I wear gloves when I’m pruning or repotting. I use a damp cloth to wipe up any sap that drips onto leaves or furniture before it dries, because once it dries, it’s a pain to remove. If I get sap on my skin anyway, I wash it off immediately with soap and water.

The sap is also toxic if ingested, which means you need to keep your Rubber Plant away from pets and kids who might chew on it. According to the ASPCA, Ficus elastica is toxic to cats and dogs. It can cause vomiting, drooling, and stomach upset. My cat has never shown interest in my Rubber Plant, but I still keep it on a high shelf just in case.

One more thing. If you’re propagating a cutting, the sap will ooze out of the cut end. You can stop the flow by dipping the cutting in warm water for a few seconds or by letting it sit until the sap coagulates on its own. Otherwise, the cutting will just keep bleeding sap all over your counter.

Above: The tools you need to fix this.

Scale insects on Rubber Plants

I found scale insects on my Rubber Plant about six months ago, and I genuinely thought my plant was growing weird brown bumps. That’s what scale looks like at first glance. Little brown or tan bumps stuck to the stems and the undersides of leaves. They don’t move, so they’re easy to mistake for part of the plant.

Scale insects are sap-sucking pests. They attach themselves to the plant and feed on its juices, which weakens the plant over time. You might also notice a sticky residue on the leaves or on the surface below the plant. That’s honeydew, which is a polite word for bug poop. It’s gross, and it can attract ants or lead to sooty mold.

Here’s how I got rid of them. First, I isolated the plant so the scale wouldn’t spread to my other plants. Then I mixed a solution of water and a few drops of dish soap in a spray bottle. I sprayed the affected areas and used a soft cloth to physically wipe off the scale insects. They come off pretty easily once you loosen them.

For stubborn cases, you can use rubbing alcohol. Dip a cotton swab in rubbing alcohol and dab it directly onto each scale insect. The alcohol dissolves their protective coating and kills them. I did this for about a week, checking the plant every couple of days and removing any new scale I found.

According to extension resources from Ohio State University, scale insects can be persistent because they reproduce quickly. Even after you think you’ve gotten rid of them, check your plant regularly for a few weeks to make sure they don’t come back. I also wiped down the leaves with a damp cloth every week to remove any honeydew and to keep an eye out for new pests.

Prevention is easier than treatment. I check all my plants once a week now, looking at the stems and the undersides of leaves where pests like to hide. I also wipe down the leaves of my Rubber Plant every couple of weeks, which removes dust and makes it harder for pests to settle in.

If you buy a new plant, quarantine it for a week or two before putting it near your other plants. I didn’t do this with the plant that brought scale into my apartment, and I regretted it.

Your Rubber Plant is tougher than you think. Most problems are fixable if you catch them early and adjust what you’re doing. Pay attention to what your plant is telling you, and don’t panic when a leaf or two falls off. Sometimes that’s just life.

References

American Society for Horticultural Science. “Environmental Factors Affecting Indoor Foliage Plants.”

ASPCA Animal Poison Control Center. “Toxic and Non-Toxic Plant List: Rubber Tree.”

Ohio State University Extension. “Scale Insects on Indoor Plants.”

University of Florida IFAS Extension. “Ficus elastica: Rubber Plant.” Environmental Horticulture Department.