Rubber Plant Leaves Curling? 9 Causes & Easy Fix!

The green, glossy Rubber plant leaves can add greenery to any corner of your house. But what if these leaves start curling? It’s not attractive at all.  

Rubber plant leaves may curl due to various factors, such as watering problems, inadequate sunlight, low humidity, extreme temperatures, fertilizer stress, pests, root-bound conditions, or environmental changes. To identify the exact cause, check and eliminate each possibility individually. 

In this article, I will go through all the reasons behind curling Rubber plant leaves and easy steps to cure them. Additionally, I will discuss some tips to prevent curling. So, let’s jump right into it without further delay. 

Why your Rubber plant leaves are curling  

I have been growing Rubber plants, or Ficus Elastica, for a long time. 

I made many mistakes and faced many issues throughout the journey. Fortunately, I overcame most of them.

Rubber plant leaf curling was one of them. 

My reasons were only a few. 

But when I shared them with people who questioned me about ways to solve curling, it didn’t work. 

So, I had to research it thoroughly. 

Today’s article is based on my research, the potential reasons I found, and easy ways to remedy them. 

First, I learned several curling patterns, for example, curling upwards or downwards, curling and yellowing/browning, leaves curling and dropping, twisting upwards with leaf spots, and many more. 

Some curling patterns share common causes, while others may have distinct reasons.

Now let’s move to the reasons and solutions: 

1. Rubber plant leaves are curling due to overwatering

One common reason for Rubber plant leaves curling is overwatering. 

When the soil remains wet for too long, it cuts the oxygen from the roots. 

When roots suffocate, they cannot breathe, hindering nutrient and moisture absorption. 

As a result, the plant curls from base to tip downwards due to the lack of resources. 

With time, roots decay, and the plant becomes susceptible to root rot infection. 

Except for curling, the other overwatering symptoms in the Rubber plant are: 

• Yellowing 
• Brown marks
• Moldy potting soil 
• Mushy stems at the base
• Foul smell, indicating root rot 

Check the soil’s moisture level. 

If the soil feels wet, stop watering and let the soil dry. 

Shift your plant to a sunny location to let the soil dry faster. 

It can also stop pathogens from causing root rot. 

Poor drainage could also be the reason. 

If it is the soil, add drainage materials to the soil, like sand, perlite, or vermiculite. 

Make sure the pot has drainage holes. 

If your plant has root rot, repot your plant to a new pot with a new, suitable soil mix. 

Please take out the plant, remove the rotten roots, remove soil from the roots, apply some fungicide, and repot it to a new pot with new soil. 

2. Rubber plant leaves curling due to underwatering

Another reason for leaf curls is underwatering. 

The plant needs water to stay consistently moist and hydrated. 

When you don’t water the plant properly, it uses the moisture stored in its leaves and stems. 

As the plant uses the moisture from the leaves and still remains dehydrated, the leaves will dry out and curl at the tips and edges.

Underwatering symptoms are: 

• Yellow leaves
• Defoliation
• Hard and dry potting soil
• Water is not penetrating the soil. 

To reverse the condition, water slowly and deeply unless the excess comes from the drainage holes. 

Make holes with a chopstick or fork to let the moisture seep into the soil and reach the roots. 

If you water correctly and still have this issue, your soil retains poorly. 

Adding peat moss or any organic matter can improve retention. 

Also read: Overwatering vs Underwatering.

3. Rubber plant leaves are curling due to low humidity

Since the Rubber plants belong to tropical rainforest areas, they need high humidity to survive. 

Humidity levels inside the house are lower than Ficus Elastica’s native land (80-90%). 

As a houseplant, the Rubber plants need around 50-60%, which is an average household level. 

The leaves won’t transpire with low humidity, and moisture will evaporate slowly. 

The leaves start curling to minimize the transpiration. 

The leaves’ moisture dries from the dry air and becomes dry and crispy.

Check the humidity level using a hygrometer to know whether humidity is the reason. 

To adjust humidity, try the following steps: 

• Mist your plants regularly. 
• Install humidifiers. 
• Keep a tray filled with pebbles and water under your Rubber plant pot. As the water evaporates, it adds humidity around. 
• Put your plant close to water tanks or aquariums. The water evaporating will add moisture to the surrounding air. 
• Group multiple tropical plants. Ensure no plant is infected, there is enough air circulation, and the leaves don’t touch each other. 

4. Rubber plant leaves are curling due to improper lighting

Both low lights and direct exposure can make the Rubber plant leaves curl. 

When the outer sides of the Rubber plant’s leaves curl upwards become pale; the reason is direct sun exposure. 

Rubber plants thrive best under bright indirect sunlight and detest direct sunlight exposure. 

It will not only curl the leaves but even scorch them. 

Other than curling, you will also notice: 

• Yellowing 
• Browning at the tips and edges 

When you see these signs, move your plant away from the window around 2-4 feet. 

Put up sheer curtains or Venetian blinds to filter the direct sunlight. 

Rubber plants can tolerate low lights, making them ideal for offices and corners. 

However, lowlights for too long result in poor chlorophyll production and yellow leaves. 

The variegated leaves start losing patterns and colors due to low chlorophyll production. 

Over time, the leaves will wilt and curl due to low energy, and the plant will become leggy. 

Shift your plant to the light source. Use Grow lights, like a broad-spectrum LED or fluorescent light, if natural light is impossible. 

5. Rubber plant leaves are curling due to temperature stress

Rubber plants are sensitive to extreme temperatures, both high and low. 

While Rubber plants can tolerate warm temperatures around 65-85°F, temperatures above 90-95°F are unsuitable. 

Extreme high temperatures can increase moisture loss and stress, especially when accompanied by too much sunlight. 

The leaves curl to preserve the moisture and protect themselves from heat. 

Increase watering to reduce heat stress and keep your plants in rooms with average room temperatures. 

If the air seems dry due to heated temperatures, increasing the humidity can help out here. 

Cold drafts are more stressful for the Rubber plants. 

Cold temperatures below 50°F break down the cell walls of the leaves.

The leaves start curling up and turn brown or black.

Remove your plant from open doors and windows from which cold drafts might enter in winter. Relocate it to a warmer room. 

During the mid-day, keep your plant close to an open window that provides bright indirect sunlight. 

It will keep the plant warm. 

If your room temperature is below 50°F, use heat lamps or heat mats to raise the temperature. 

You can keep your plant in rooms containing HVACs, but ensure they are not close to the unit. 

Maintain at least 10-15 feet between your plant and the unit. 

6. Rubber plant leaves are curling due to pest infestation and diseases

Rubber plant pests (aphids, mealybugs, spider mites, and scale insects) can change the leaf shape and make them curl. 

When the bugs attack the plant, the leaves curl for survival. 

As the pests suck the sap from the leaves, they distort the leaves, dehydrate them, make them curl, and cause discoloration. 

A stressed plant can also invite pests. 

For example, a dehydrated plant invites thrips and spider mites, and high moisture invites aphids, mealybugs, and scales. 

A healthy Rubber plant can easily overcome the issue, provided you treat it correctly at the right time. 

It takes time for a weak plant to recover. 

Except for curling, the other signs of pest infestation are: 

• Yellowing or browning 
• Defoliation 
• Plant leaf deformation  
• Holes on the leaves 
• White spots 

The best way to deal with houseplant pests is to inspect your plant daily and take immediate steps for an early intervention to stop it from spreading. 

To save an infected plant, here are the steps to follow: 

• Quarantine your infected plant. 
• Shower the plant to dislodge the pests from their place. 
• Use neem oil solution and spray it on the infected areas. Concentrate under the leaves and the stems. 
• Apply rubbing alcohol on areas where you suspect the pests with a cotton ball. 
• Release lacewings and ladybugs to let them eat the bugs.
• If the pests are stubborn, you might have to kill them with insecticidal soaps and pesticides. 

Black spot disease is a common disease that makes the Rubber plant leaves curly. Other signs are: 

• Yellow or brown leaves 
• Black spots on the leaf surfaces 
• Withered look 

The pathogens of this disease attack the leaf cells. 

As it slowly takes control, it kills the entire plant. 

Water droplets on the leaves encourage the disease to spread and produce spores. 

First, isolate the plant and cut off the infected leaves. 

Natural fungicides might not work here. 

So, try this Earth’s Ally 3-in-1 Plant Spray Concentrate to treat the disease. 

7. Rubber plant leaves curl due to root-bound 

When the plant becomes extremely root-bound, there will be more roots than soil. 

As the soil reduces, it can’t hold enough moisture. 

Curling helps the Rubber plant leaves conserve moisture. 

Apparent signs of root bound are:

• Roots circling the pot
• Swelling pot
• Roots coming out of the potholes
• Leaves yellowing
• Slow or stunted growth. 

Repot your Rubber plant once a year during its active months when you see roots from the drainage holes. 

Make sure to use a pot 1-2 inches bigger than the old one, which must have drainage holes. 

Use new soil, too. The old soil has lost its abilities, and the new soil can encourage fast growth. 

8. Rubber plant leaves curling due to environmental changes

Stress from sudden environmental changes in the Rubber plants can stress the plant. 

Repotting the Rubber plants, propagating them, or shifting them to a different location can shock the plant. 

Curling, yellowing, or browning are signs of stress. 

The plant will take time to adjust to the environmental change and recover. 

Once it recovers, these signs will disappear. 

Provide the plant with bright, indirect sunlight for 5-8 hours, ensure consistently moist soil, and protect it from cold drafts. 

If you are recently repotted, don’t fertilize for a few weeks since the new soil will provide the nutrients. 

Repot and propagate during the spring and summer. 

The plant can recover and adjust to its new environment faster. 

9. Rubber plant leaves are curling due to fertilizer stress 

Nutrient deficiency occurs when you don’t fertilize the plant. 

Even if you use fertile soil, it alone can’t provide all the nutrients. 

Lack of nutrition can make the Rubber plant’s leaves curl upwards or downwards. 

For example, magnesium deficiency makes the leaves curl upwards at the margins, especially the older leaves. 

Phosphorus deficiency causes the leaves to turn upwards. 

Except for these, you will notice other signs like stunted growth or interveinal leaf chlorosis. 

To fix this issue, start feeding your plant. 

Begin with a quick and light dose using a balanced liquid fertilizer. 

Whenever my Rubber plant suffers from underfeeding, I mix ⅛th teaspoon of Bonide Liquid Plant Food 10-10-10 with a quarter of water and use it for a quick nutrition boost. 

Make sure you don’t over-fertilize your Rubber plant. 

Overfertilization can also make the Rubber plant leaves curly. 

Excessive feeding increases salt accumulation on the soil surface, which can, over time, reach the roots and burn them, further hindering nutrient or moisture uptake. 

The plant gets stressed and starts curling its leaves. 

Other signs are leaf discoloration and stunted growth. 

To remedy the condition, stop feeding and flush off your soil. 

Keep watering thoroughly unless water and salt come out of the drainage holes. 

Let the soil dry, and repeat the process 2-3 times until clean water drains out of the holes. 

To avoid salt accumulation, flush the soil every month. 

Need a correct fertilization schedule? Follow this: 

• Fertilize your Rubber plant once a month or every 2-4 weeks during the spring and summer. 
• If you use a slow-release or organic fertilizer, apply it every 4-6 weeks during the growing months. 
• Cut back in the fall and completely stop feeding in the winter. 

5 less likely reasons for making the Rubber plant leaves curly 

You have learned all the common reasons for curling Rubber plant leaves. 

Except for these, there are a few more reasons. 

Though these are less likely to happen, it is better to stay aware of them. 

Whenever the problem occurs, you can fix it.  

Let’s have a quick look: 

1. New leaf growth 

One day, one of my readers couldn’t find any issue behind the leaf curling and emailed about it with a photo. 

Upon close examination, I discovered the leaves were new and still developing, and I informed her immediately. 

Whenever the Rubber plant develops new leaves, they remain tightly curled. 

As they develop, they will slowly uncurl. 

The leaves are green and not yellow or brown. 

The method is natural. Be patient and see how the leaf unfurls. 

2. Soil contaminants and chemical exposure 

Soil can sometimes be the culprit behind curly Rubber plant leaves. 

I am talking about soil contaminants. 

Contaminants from pesticides or fertilizer residues containing harmful chemicals can affect the plant’s nutrient and moisture uptake and reduce the soil’s beneficial micro-organisms and soil fertility. 

If you suspect this issue, send your soil for a test. 

Once the problem is confirmed, repot your Rubber plant with new potting soil. 

Change your fertilizer and pesticide.

To avoid this issue further, choose organic fertilizers and insecticides or try natural methods to treat bugs.  

3. Using intense leaf cleaning products 

Some gardeners use commercial Leaf Shine products to clean and shine the Rubber plant leaves. 

While they can be used, they cause damage due to the presence of harsh chemicals. 

These products create a barrier on the surface, blocking solar absorption, photosynthesis, and transpiration. 

The leaves start curling due to stress. 

According to my experience, prevention is the best cure. 

First, test it on one leaf. 

Once you see positive signs, use it for the other leaves. 

Opt for other methods involving plain, filtered water: 

• Regular misting. 
• Take lukewarm water and wipe the leaves with it using a soft cloth. 
• Dust the leaves with soft water. 
• Shower your plant 

If you need a cleaning solution for stubborn dust, mix water with a few drops of: 

• Vinegar 
• Lemon juice 
• Mild dish soap 

If you still want to use these products, check the label and instructions given. Avoid products containing harmful chemicals. 

4. Dirty leaves 

Leaves absorb sunlight and undergo photosynthesis. 

Dirty leaves can block these procedures. 

Due to stress, the plant becomes weak, and the leaves begin to curl. 

Make sure to clean the leaves once a month. 

Use the methods I have shared in the previous point. 

We also have an article about Cleaning the Rubber plant leaves. 

You can read it for detailed information.

5. Natural Aging 

Old leaves in the Rubber plant may start curling. 

They also turn yellow or brown and fall off the plant. 

It is normal, and you can’t remedy it. 

Prune the leaves instead of waiting for them to fall off. 

This will encourage new leaves and make your plant look good. 

How do we prevent the Rubber plant leaves from curling? 

Now that you know all the common and uncommon reasons, you should have some extra suggestions to prevent this from occurring. 

Here are some tips I use for my Rubber plants, and I recommend you follow them: 

• Let the Rubber plants have bright indirect sunlight. If the plant is near a south-facing window, put up sheer curtains or Venetian blinds to filter the plant, or keep the plant 2-3 feet away from the window. Else, you can choose a west or east-facing window. You can also use Grow lights. 
• Water the Rubber plant whenever the top few inches have dried. Don’t follow any strict routine. 
• Make sure to use soil with proper drainage, retention, and nutrition. 
• Fertilize the plant monthly with a balanced liquid fertilizer during the spring and summer. Avoid it in winter. 
• The ideal temperature should range around 60-80°F. It should neither go below 50°F nor cross 90°F. 
• Maintain 50-60% humidity levels. Use a hygrometer to check the accurate humidity, and adjust it by routine misting, installing humidifiers, grouping, using pebble trays, and plants near aquariums. 
• Repot the plant once a year during the spring or summer. Take care of the plant to help it recover from stress faster. Don’t fertilize for a few weeks. Give your plant time to adjust to the new environmental changes. 
• If you have propagated, take care of the parent plant with the other plantlets to help it recover faster. Always propagate in the spring or summer. 
• Keep an eye out for pests. If you find any, take immediate steps to prevent spreading. Avoid using insecticides and pesticides containing harsh chemicals. First, try natural methods like showering, rubbing alcohol, or neem oil. If they don’t work, then go for commercial pesticides. Of course, ask for suggestions from experts to avoid chemical contamination. 
• Prune your plant regularly once a year during the growing months to encourage bushy growth and keep the plant in shape. 
• With these tips, you can prevent leaf curl in the Rubber plant and keep them healthy. 

Note: Remember that the curly leaves may or may not return to their original shape. Wait and see if the leaves return to their original shape after treatment. If not, prune the affected leaves. It will encourage new leaf growth. 

Final thoughts 

Rubber plant leaves curling is a familiar issue, like yellowing, browning, or stunted growth. The common causes of curling are improper watering, low humidity, temperature stress, bad light conditions, fertilizer stress, pests, or environmental stress caused by repotting or propagation. 

Since many reasons are involved, you must check each to rule out the wrong one, find out the actual cause, and troubleshoot it soon. You can check for the other signs besides curling for each cause to find out the real issue. Pay attention to the less likely reasons. 

Check your plant closely every day to see how it is doing. Early inspection can prevent the problem from spreading and stressing your plant too much. Follow the prevention tips I have shared to keep your plant from curling. 

Reference: Rubber plant Wikipedia