Rubber Plant Leaves Turning Yellow? 7 Reasons Why

It is common for the Rubber plants to have yellow leaves once or twice a year. Seeing the lovely green leaves in the Rubber plant turning yellow is not appreciable. Whether yellow leaves are a concern depends on the specific issue your plant is facing.

Rubber plant leaves turn yellow due to improper watering, poor drainage, inadequate light, fertilization issues, cold drafts, infestations, and root-bound. Improve care with good watering, drainage, fertilization, and strategic repotting. Don’t let cold drafts or pests ruin your plant. 

Since there are multiple reasons, this article will help you learn how to spot and treat them early and keep your plant thriving for prolonged periods.  

1. Rubber plant leaves are turning yellow due to watering issues

Both overwatering and underwatering can have yellow leaves in the Rubber plant. 

Both hinder the plant’s ability to absorb moisture and nutrients, causing it to fail to meet its requirements. 

It further affects photosynthesis and chlorophyll production, leading to yellow leaves. 

Now, let’s understand how overwatering and underwatering affects the transfer of nutrients and moisture: 

Leaves turning yellow due to Overwatering 

Rubber plants don’t love sitting over water. 

They enjoy consistently moist soil. 

Watering too much cuts off oxygen, suffocates the roots, and hinders moisture and nutrient uptake. 

It further affects the plant’s regular functions, causing the leaves to turn yellow, wilt, and fall off. 

Whenever your plant starts showing yellow leaves, here’s what you should do: 

• Check the soil. If it feels wet, stop watering immediately and let the soil dry out. 
• Let the plant have enough indirect sunlight. It can help dry out faster. 
• If you feel that the plant is suffering root rot, you must take out your plant and repot it after pruning the infected roots. Spray some fungicide to avoid the spreading of the fungal spores. 

Leaves turning yellow due to Underwatering 

Many people try to prevent overwatering but end up dehydrating the plant. 

Underwatering can also have yellow leaves. 

With dry soil, the plant struggles to uptake the moisture and nutrients from the soil, leading to discolored and fallen leaves. 

However, underwatering causes much less harm than overwatering, and the solution is also easy:  

• Check the soil and start watering if it feels dry. 
• If the soil is hard, use a fork or a chopstick to make holes. It will allow the moisture to reach the roots directly. 
• Remove the yellow leaves from the plant. Once you start watering and the plant recovers, it will grow new leaves instead of wasting time reviving the discolored leaves. 

If you often tend to underwater your plants, you can use plastic or self-watering pots. 

Practicing watering techniques 

• Water your Rubber plants once a week with 1 inch of water throughout the spring and summer.
• Instead of following any routine, check the soil’s moisture level before watering. The top 2-3 inches must dry before watering the plant. 
• I prefer deep but infrequent watering. It will keep the soil moist for a long time, and proper gaps can be maintained to let the soil dry out. 
• During the winter, you can reduce watering. Since Rubber plants go dormant, moisture requirements will be less. Check the moisture level and water the plant every 2-3 weeks. 

Also read: Overwatering Vs Underwatering Plants: Signs, Fix & More.

2. Rubber plant leaves are turning yellow due to poor drainage

Drainage is an additional factor that affects the plant’s watering issues. 

Poor drainage in both soil and pot can affect the Rubber plant’s health and lead to yellow leaves. 

Soil moisture and drainage 

The soil you use for the Rubber plants must be well-drained and well-retained. 

Soil with poor drainage holds water for too long, leading to overwatering, which further causes yellow leaves. 

Also, soil with poor retention qualities fails to hold enough moisture and nutrients, affecting the plant’s health and daily functionality and can cause yellowing, browning, or defoliation. 

If soil is the issue, you must amend it with the right ingredients. 

For example, add perlite or vermiculite to improve drainage if drainage is the issue. 

To retain moisture, add peat moss or organic matter to the soil. 

The organic matter can also make the soil fertile and provide necessary nutrients to the soil until you start feeding. 

Check our soil article to learn in detail about Rubber plants’ soil requirements and recipes. 

Pot drainage matters 

Along with the soil, the pot’s drainage system also affects the plant’s health and leads to yellowing. 

A pot must have drainage holes so that the excess moisture can escape. 

Otherwise, the water stays stagnant, roots get affected, the plant gets stressed, and causes yellowing or browning. 

Make sure your pot has enough drainage holes. 

Consider the material, too. 

If you overwater by mistake, go for terracotta pots. 

Their porosity can wick away moisture faster.

If you forget to water often, go for plastic pots. 

You can use self-watering pots for the best results. 

Please fill the reservoir; the plant will absorb moisture as needed. 

3. Rubber plant leaves are turning yellow due to environmental factors

Environmental factors can lead to yellow leaves in rubber plants. 

It commonly involves the surrounding temperature, humidity, and sunlight availability. 

Though you cannot control the environmental changes, you can make a few adjustments. 

Let’s have a look. 

Temperature changes and cold drafts 

Rubber plants enjoy warm temperatures ranging between 60-80°F. 

Rubber plants don’t react well to sudden temperature ranges. 

They need the surrounding temperature to be consistently warm. 

Whenever the plant receives extremely hot or cold drafts, leaves turn yellow due to stress. Over time, it can drop off the plant. 

It happens when the weather becomes extremely hot or cold, or your plant is in a room with an HVAC system. 

When you see yellow leaves, consider the temperature and place the plant somewhere that keeps the temperature consistent. 

Do not place your Rubber plants close to open windows or central heating or air conditioning vents. 

If your plant is in a room with HVAC, maintain an average temperature and keep the plant at least 10 feet away from the unit. 

Inadequate sunlight 

Rubber plants love bright, indirect sunlight throughout their life. 

Insufficient light or sudden changes in the light conditions can affect the plant’s health and lead to yellow leaves. 

Rubber plants endure low lights, but extreme lowlights from too long affect chlorophyll production, leading to yellow or brown leaves. 

Sudden light changes shock the plant because it doesn’t get enough time to adjust to the new conditions. 

As a result, the leaves turn yellow and start dropping. 

You must shift your plant to a location with 6 to 8 hours of bright, indirect sunlight. 

An east or west-facing window provides good sunlight in my region. 

If you don’t have windows in such directions, you can use Grow lights for the plants. 

Keep the Grow lights on for 10-12 hours, then turn them off. 

Maintain 6 to 12 inches of distance between the light and the plant. 

Don’t expose your plant to direct sunlight. 

Put up sheer curtains or Venetian blinds if you have a direct sunlight window. 

Also, do not change your plant’s light conditions suddenly. 

Make sure it remains consistent. 

If you must expose it to direct sunlight (needed in winters when the sun intensity and duration reduces), don’t forget to acclimate for 7 days. 

Low humidity 

In their native land, the Rubber plants receive 70-80% humidity. 

But that’s not possible indoors. 

Rubber plants need around 50-60% humidity levels indoors. 

Humidity levels below 50% mean the surrounding air is dry. 

The leaves lose moisture faster and dry out with dry air, leading to yellow or curly leaves. 

If you are unsure about the issue, install a hygrometer to understand the accurate humidity level of the room. 

Next, adjust humidity levels by the following methods: 

Mist your Rubber plants regularly. 

Install humidifiers. It is beneficial if you have multiple tropical plants in one room. 

Put a pebble tray with water under the pot. As moisture evaporates, it adds humidity. 

Place your plant close to the water tanks or aquariums. Water can evaporate and add humidity to the air. 

Group multiple tropical plants. Keep space between each, and don’t let the leaves touch each other. 

4. Rubber plant leaves are turning yellow due to fertilizing issues

Both overfeeding and under-fertilizing can affect the Rubber plant’s health and make the leaves yellow. 

The typical houseplant fertilizers contain a balanced nitrogen, phosphorus, and potassium ratio. 

The yellow leaves in the Rubber plant mainly result from a lack of nitrogen or potassium. 

Remember I shared how incorrect watering affects the nutrient and moisture uptake and turns the leaves yellow? 

Lack of proper nutrients will affect the plant’s health and lead to yellow leaves. 

Over-fertilization can also affect rubber plants and cause yellowing. 

Excessive salt accumulates on the soil and reaches the roots. 

It can further burn the roots and make it difficult for the plant to absorb moisture and nutrients. 

For this, the leaves might turn yellow or brown. 

Fertilization issues affect the lower leaves first, but you will often see signs in many leaves, and they are not on the lower side. 

Except for yellow leaves, you will find defoliation and stunted growth. 

You can use a soil rapitest (Luster Leaf 1601 Rapitest Test Kit for Soil pH, Nitrogen, Phosphorus, and Potash) to test for each nutrient’s pH levels and availability individually. 

If you have under-fertilized your plant, start fertilizing your Rubber plant. 

For a quick dose, use a water-soluble or liquid fertilizer. 

If you have not used the soil rapiest, choose a balanced fertilizer with NPK 10-10-10. 

Apply fertilizers every 2-4 weeks throughout the growing season. 

When you have confirmed that your soil has any nitrogen or potassium deficiency, use fertilizers with higher ratios of these nutrients. 

If you have over-fertilized, stop feeding and flush your soil. 

Water deeply to flush the soil unless excess comes out. 

Continue this until you see clean water draining out of the drainage holes. 

Stop feeding for a few weeks until you see signs of recovery. 

Then, you can start feeding again. 

Always dilute your fertilizer to half the recommended strength, use less frequently, and stop feeding in the winter. 

5. Rubber plant leaves are turning yellow due to pests and insect concerns

Rubber plants, though hardy, can attract pests under favorable conditions. 

Common pests like aphids, mealybugs, scales, mites, and whiteflies suck the plant sap, turning the leaves yellow. 

Over time, the leaves become distorted and fall off the plant. 

If you suspect yellowing results from pest infestation, inspect the plant closely using a flashlight and concentrate on the leaf’s underside. 

Once you have confirmed the issue, here’s what you should do: 

• Isolate your plant and remove the infected parts of the plant. 
• Shower your plant to dislodge the pests from their place. 
• Spray neem oil on the infected areas. 
• Take some rubbing alcohol on a cotton ball and wipe the pest-infected areas to kill the bugs. 
• If these don’t work, use insecticidal soaps or pesticides. 
• Try systemic methods. The plant will absorb the insecticides. Once the bugs suck the sap and ingest the insecticide, they will die. 

6. Rubber plant leaves are turning yellow due to pot-bound plants

Rubber plants grow moderately to fast, so they can become root-bound.

Since pots have a limited space, the roots get crumpled after one point in that limited space. 

If you don’t repot, the roots will keep growing, and your pot will have more roots than soil. 

As the amount of soil reduces, the supply of water and nutrients also decreases, further causing yellow leaves, browning, or stunted growth. 

Therefore, repot your Rubber plants once every year during the active months.  

If you are unaware of the right repotting time, check whether the roots are coming from the drainage holes. That’s the right time to repot. 

While repotting, choose a pot 1-2 inches bigger than the recent one. 

It will give enough room for the roots to grow for a year. 

Your plant may receive a repotting shock. But don’t worry. 

Keep caring for the plant, and avoid feeding it for a few weeks until you see new foliage growth. 

Repot during the spring or summer. As the plant grows actively, it can heal faster from the shock. 

7. Rubber plant leaves are turning yellow due to aging

Not every time, the reason behind yellow leaves is incorrect cultural practices or environmental factors. 

Sometimes, leaves turn yellow or brown simply due to aging. 

If you are doing everything correctly and still see some lower leaves turning yellow, it could be because of aging. 

These leaves will fall off independently, and new leaves will grow in your plant. 

So, there is no solution, and you don’t have to worry about it. 

Final thoughts 

Whenever you find the Rubber plant leaves yellow, take some time to find out why. Improper watering, poor drainage, environmental factors like temperature, sunlight, humidity, fertilizing issues, pest infestations, and root-bound. Check each of them to find out and troubleshoot the right issue. 

Water the plant whenever the top few inches have dried, ensure good drainage in the soil and pot, maintain a warm temperature, provide 6-8 hours of indirect sunlight, maintain 50-60% humidity, and fertilize every 2-4 weeks throughout the active months. Check out for pests and take immediate action if you notice any infestation. 

Repot your plant once a year during the active seasons. Keeping caring for the plant for fast recovery from repotting shock. If you are doing everything well and still see yellow leaves, it is just aging. Don’t worry, as new leaves will grow after some time. 

Reference: Rubber plant Wikipedia