Fertilizer For Rubber Plant: What Kind, How Much & More

If you’ve been growing Rubber plants for a while, you’ve likely seen significant growth. Rubber plants can grow several inches tall when they get sufficient nutrients. 

Fertilizing supplies essential nutrients and minerals to the Rubber plants. Feed them every 2-4 weeks during the growing season with a liquid fertilizer. Since Rubber plants are not heavy feeders, too much fertilizer can cause leggy growth and fertilizer burns. Avoid fertilizing during the winter. 

This guide covers the importance of fertilizing Rubber plants, when and how to do it, recommended frequencies and schedules, best fertilizers, NPK ratios, and the consequences of improper fertilization. By the end of this article, you’ll have a good grasp of Rubber plant fertilization, so read on. 

Rubber plant Fertilizer basics: Do they need fertilizers? 

I receive a lot of questions from the Rubber plant growers about whether they need fertilizers or not, when and how often to apply, NPK ratios, and several other doubts. 

Rubber plants benefit a lot from fertilizing. 

It gives them a boost of nutrition and encourages healthy growth.

When Rubber plants receive sunlight, water, and carbon dioxide, they create food through photosynthesis. 

The food provides energy and helps the plant survive. 

Aside from energy, the plant needs nutrients and minerals for its internal structures and chemical reactions.

Soil does provide nutrients, but it alone cannot provide enough. 

Ultimately, you must feed them with fertilizers for proper nutrition. 

Nutrients from fertilizers play a significant role in the growth and development of Rubber plants. 

It is important to note that all fertilizers are not ideal. Choosing the right fertilizer, specially made for Rubber plants, will be a great choice.

Nutrients	Role
Nitrogen	-Essential for photosynthesis -Helps stimulate growth of leaves and foliage
Phosphorus	-Encourages root growth -Essential for flowering and fruiting plant
Potassium	-Helps regulate water intake -Helps fight off diseases -Makes plants resilient

Fertilizer composition and nutrients needed by the Rubber plants 

Now that you know that Rubber plants need fertilizers, you would want a suitable fertilizer. 

Learning about the ideal nutrients can help you choose the houseplant food containing the suitable nutrients in the right composition and ratio easily. 

Nutrients the Rubber plants need 

Rubber plants will need both macronutrients and micronutrients. 

The primary nutrients are nitrogen, phosphorus, and potassium. 

Here’s what these nutrients do: 

• Nitrogen helps in the growth of leaves and stems. It is also essential for plant photosynthesis. 
• Phosphorus helps in nutrient transport, photosynthesis, protein synthesis, energy transmission, and carbohydrate decomposition. It develops the root development, fruits, seeds, and flowers. 
• Potassium helps develop strong stems and a suitable growth rate while increasing the plant’s resistance to fight droughts and infestations. 

Except for these, the micronutrients are equally crucial for the plant’s overall growth and development, for instance, iron, magnesium, calcium, manganese, and zinc. 

Make sure that the fertilizer you use contains these nutrients as micronutrients. 

NPK ratio 

Every plant will need 3 major nutrients – nitrogen (N), phosphorus (P), and potassium (K). 

The term NPK stands for these three nutrients. 

Rubber plants benefit from a balanced fertilizer with an NPK ratio of 10-10-10 or 20-20-20. 

If your fertilizer has an NPK ratio of 10-10-10, it contains 10% nitrogen, 10% phosphorus, and 10% potassium. 

So, this is a balanced fertilizer. 

A fertilizer with an NPK ratio of 3-1-2 or 3-1-3 promotes healthy leaves and overall plant development. 

If you have a mature Rubber plant, the NPK ratio for mature Rubber plants is 24-8-16. 

The ratio can encourage good vegetation growth and improve root development. 

Remember not to use fertilizers containing excessively high nitrogen levels. 

Fertilization frequency and schedule for the Rubber plants 

Rubber plants are not high feeders. 

Too much fertilization can burn the roots and cause stunted growth. 

At the same time, lack of fertilization causes weak and slow growth. 

Therefore, understanding when and how often to fertilize the Rubber plants is crucial to feeding them correctly while keeping them thriving. 

The right time to fertilize the Rubber plants is spring and summer. 

These are the seasons when the plant is actively growing. 

Hence, providing fertilizer accurately at these times ensures a boost of nutrition and enhances their growth. 

Another thing to consider is the fertilization frequency. 

The frequency depends on what type of fertilizer you use. 

Liquid fertilizer works instantly. Feed the Rubber plants every 2-4 weeks or once a month throughout the growing season with a liquid fertilizer. 

Slow-release takes time but evenly distributes the nutrients. 

If you use a slow-release fertilizer, extend the frequency to every 4 to 6 weeks.  

As fall arrives, the plant stops growing. 

At this time, cut back fertilizing slowly and entirely stop it in winter. 

The plant rests and goes dormant in the winter. 

So it doesn’t absorb any moisture or nutrients. 

Feeding would only lead to over-fertilization. 

Fertilizer types for Rubber plants and application methods 

Several types of fertilizers are available. 

You can use them all for the Rubber plants, but you need to be careful to avoid any chemical contamination. 

Let’s have a quick look at the different fertilizer types and their application: 

Organic fertilizers vs. Synthetic fertilizers 

Organic fertilizers are made from natural sources. 

They are eco-friendly but expensive because they are minimally processed, and nutrients take time to be immediately available to the plants. 

Organic fertilizers break down slowly and provide nutrients over extended periods. 

One proper application will last for several weeks. 

On the other hand, synthetic fertilizers are made of components that are highly processed. 

As a result, they are highly concentrated and precise in their NPK ratios. 

Synthetic fertilizers break down very quickly. 

Some organic fertilizers are: 

• Compost 
• Alfalfa flour 
• Fish emulsion 
• Manure 

You can apply the organic fertilizers in several methods: 

• For topdressing, you can add fertilizers to the soil surface once every 
• You can make compost tea out of compost and use it.  

Since the organic fertilizers slowly release their nutrients, one application can last for weeks. Use them once every 4-6 weeks. 

If you use synthetic fertilizers, like a 10-10-10 fertilizer, dilute it around 50% and apply them once a month. 

You can make liquid fertilizers from the organic fertilizers and use them monthly. 

Mix them with water and use it once every 3-4 weeks. 

Liquid vs. slow-release fertilizers 

Liquid fertilizers work quickly, allowing plants to absorb them faster than slow-release options. 

On the contrary, slow-release fertilizers (granules, pellets, or spikes) slowly release the nutrients to the soil in the correct ratio.  

Using slow-release fertilizers keeps the potting mix well-nourished so that the plants can use them whenever they need. 

However, it becomes problematic when the plant has a nutrient deficiency. 

In such conditions, the plant will need a quick boost to recover from the deficiency faster.  

Whenever people ask me how to fix a nutrient deficiency quickly, I suggest using liquid fertilizers. 

Liquid fertilizers work instantly, give a quick nutrition boost, and help the plant recover quickly. 

They come in concentrated or powder form to be diluted in water. 

The amounts are already mentioned on the packages. 

Dilute the fertilizer properly to make it easier for the plant’s roots to absorb and reduce fertilizer burns. 

If you use liquid fertilizers, dilute ¼th of the product with water and make the strength to half. 

Pour it slowly around the plant on the soil surface and water it. 

Use it once every 2-4 weeks throughout the spring and summer. 

If you use granules, spread some around the plant and water the plant.

If you use spikes or pellets, take a few (check the package label or ask the store staff), add them to the soil, and water the plant to activate the nutrients. 

Use slow-release fertilizers once every 4 -6 weeks in the active months. 

Best fertilizers for Ficus Elastica (Rubber plants) 

All the types mentioned above are ideal for Rubber plants. 

Each of them provides different benefits to the plants. Here’s a guide to understand it: 

• Balanced slow-release fertilizers provide a well-rounded mix of the proper nutrients. Find slow-release formulas as they slowly release nutrients and ensure a steady supply. 
• Organic fertilizers can enrich the soil with organic matter and promote beneficial microbial activity to improve the soil structure. They provide nutrients slowly without the risk of chemical contamination. 
• Liquid fertilizers are quick and easy to apply as you can apply them directly to the soil and give a quick boost of nutrition. They have various formulations, including balanced and specially formulated for foliar application. 
• Commercial fertilizers are primarily made for Rubber plants. These have additional micronutrients that can satisfy the plant’s specific needs. 

Fertilizer risks in the Rubber plant 

Whether you are a beginner or an experienced gardener, your plant will face fertilizer risk at one point. 

Using too much or too little fertilizer can be harmful. 

Luckily, we can address these problems, but we need to act promptly, especially when it comes to overfeeding.

So, how will you understand these issues, reverse them, and help the plant recover? 

Let’s understand. 

Nutrient deficiency or under-fertilization in the Rubber plants 

When your Rubber plants don’t receive enough nutrients, they will show signs of deficiency. 

The potential signs of fertilizer deficiency in Rubber plants are: 

• Brown leaves 
• Stunted growth 
• Young leaves are yellowing and falling off 
• Necrotic tissues in young leaves 
• Dark green leaves with yellow veins 
• Wilting of the older leaves 
• Green leaves with a reddish tint 
• Weak stems and branches 

If you observe your plant regularly, you will see these signs on your plant when you don’t fertilize properly. 

It doesn’t happen after one missed dosage. 

You will see the symptoms when you don’t fertilize the plant continuously for months. 

To overcome this issue, begin with a quick and light dosage of liquid fertilizer once a month. 

Since it works instantly, it can provide a quick boost of nutrition. 

Once it starts recovering, you can choose a different fertilizer. 

Don’t forget to water the plant before and after application. 

Over-fertilization risks for Rubber plants 

Too much of anything is always harmful. 

The same is true for Rubber plant fertilization. 

Excessive fertilizers can burn the root system and make it difficult for the plant to uptake nutrients and moisture. 

It happens when you fertilize too often, use strong fertilizers, or feed the plants in winter. 

First, you don’t have to feed the plants too often. 

Feeding once a month with liquid fertilizers or every 4-6 weeks with slow-release is enough. 

Second, you must dilute your fertilizers very well with water. 

Check the packaging and see how strong they are. Always dilute it by 50%. 

Third, Rubber plants stay dormant in winter and don’t absorb any nutrients. 

When you over-fertilize, the salts from the fertilizers accumulate on the soil and, over time, burn the roots. 

Common signs of fertilizer burns are: 

• Yellowing 
• Scorches on the leaf surfaces. The leaf tissues are delicate, and they can quickly get burned by excess chemicals and salts. 
• Browning at the tips and edges 
• Stunted growth
• White crust layer on the soil surface 
• Signs of underwatering and underfeeding. The plant struggles to uptake the nutrients and moisture due to fertilizer burns. 
• Over time, pests will start wandering around the plant. Don’t let it reach this stage. 

If you see these signs and suspect over-fertilization, follow these steps to help the plant recover: 

• Remove the badly scorched and damaged leaves from the plant. 
• Consider deep watering until the excess comes out of the drainage holes. With the water, the excess salts will flush out. 
• Let the soil dry a bit and water again. Do this 2-3 times until clean water comes from the drainage holes. 
• Stop watering. Next, watering should be done when the top few inches have dried. 
• Stop fertilizing for the time being. Once you see signs of recovery and your plant is doing well, fertilize in minimal amounts less often. 

Remember that less is more. Even if you apply less fertilizer once a month, that will also work. 

Fertilizer recommendations for the Rubber plants (both commercial and DIYs)

If you need fertilizer recommendations without research, I can assist. 

Here, I will share both commercial and natural fertilizers so that you don’t have to put too much time and effort into finding or making the right one. 

Let’s start with commercial fertilizers. They are easy to use and easily affordable: 

• Jack’s Classic Water Soluble All-Purpose Fertilizer
• Miracle-Gro Liquafeed All-Purpose Plant Food
• Liqui-Dirt Nano Powder All-Purpose Organic Complete Plant Food

I would also like to share some DIY organic fertilizers I often use for my Rubber plants and other houseplants. 

If you are a beginner, try these: 

Compost 

• Collect kitchen trash, like fruits and vegetable peels, coffee grounds, and eggshells. 
• Mix them in a compost bin. It will ensure a good balance of green for nitrogen-rich and brown for carbon-rich materials. 
• Turn the compost periodically to increase the decomposition speed. 
• Over time, the organic matter will break down and become a nutrient-rich compost used for the Rubber plants. 

Vermicomposting 

• Make a worm composting bin with a mix of bedding materials like newspaper or cardboard, and add composting worms, like red wigglers. 
• Feed them kitchen scraps. Avoid meat, dairy, and oily food. 
• As the worms consume this waste, they produce dark rick vermicompost as a natural fertilizer. 

Manure tea 

• Gather well-aged manure from cows, horses, and rabbits in a porous bag or container. 
• Dip the container in a bucket of water. 
• Let it soak for some days; stir it occasionally. 
• Water will gradually absorb the nutrients from the manure and become a nutrient-rich liquid fertilizer. 
• Dilute the liquid with water until it becomes brown, and use it in the plant. 

Banana peel fertilizer 

• Cut banana peels into pieces and bury them in the potting soil around the plant base. 
• As the peels decompose, they release phosphorus, potassium, and other nutrients in the soil. 

Epsom salt 

• Add one tablespoon of salt to one gallon of water and use it in the plant. 
• The magnesium in the salt will enhance chlorophyll and overall plant health. 

Seaweed fertilizer 

• Remove the excess salt from the seaweed and soak it in water for some days. 
• Remove the seaweed and use the nutrient-rich water to water the plants. 
• The seaweed extract will add the essential nutrients and promote plant growth and stability. 

Enhancing Rubber Plant Growth 

Fertilizing enhances the Rubber plant growth. 

But proper application by following the instructions and feeding at the right time with the right frequency is what matters the most. 

Here, I will share some tips for you to follow whenever you fertilize the Rubber plants: 

• Select the right fertilizer for the Rubber plants. All the types I have mentioned will work well. I suggest a slow-release, balanced fertilizer for a gradual and continuous supply of nutrients. You can also use organic fertilizer to reduce chemical buildup and burns. 
• Always feed your Rubber plants during the active months. Spring and summer are the months when the plant thrives. Fertilizing will increase their growth and make them healthy. 
• Don’t overfeed. If you are confused, use fewer amounts or apply less frequently. Flush the soil once a month to avoid burns. 
• Watering and fertilization is a balanced approach when you fertilize the plants. Water the plants thoroughly before and after application. It will prevent the roots from absorbing too much strong fertilizers and reduce burns.
• Proper light plays a critical role in plant growth. Monitor the light conditions and ensure the Rubber plant receives sufficient, bright, indirect sunlight. It also allows the plant to use nutrients effectively. 
• Regular pruning will encourage more growth and keep the plant in shape. Remove the discolored and dead leaves, then remove ⅓rd leaves or stems to keep the plant in the desired shape and height. 

Final thoughts 

Fertilize Rubber plants during their active growth seasons. Fertilizing them provides them with a boost of nutrition, further encouraging healthy growth and fast development.

Feed the Rubber Plants every 2-4 weeks with a balanced liquid fertilizer or 4-6 weeks with a slow-release. Avoid it during the winter. Fertilizing during the dormant season causes over-fertilization because the plant doesn’t absorb any nutrients while resting. 

Fertilizing too much can result in fertilizer burns, yellowing, scorched leaves, and stunted growth. If you have over-fertilized your plant, stop feeding and flush the soil by thoroughly watering 2-3 times until the excess salts drain out and fresh water is visible.

You can use several fertilizer types, like slow-release, liquid, organic, or commercial fertilizers. 

If you notice signs of nutrient deficiency, use a liquid fertilizer for an instant boost. Otherwise, you can use any one of your choices.

Provide proper watering before and after feeding, give the plant enough indirect sunlight, monitor it, and prune regularly to maintain its shape. 

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Reference: Rubber Plant Wikipedia