Signs of Underwatered Rubber Plant (And How to Revive It)


Like many top-end indoor plants, the rubber plants do a great job at pulling the room together. Especially with the fact it’s a rainforest variant that has eye-catching oval shiny plum leaves along with an overall sleek build.

But without enough water, the rubber plant’s style depletes. As it’s drying leaves, and a wobbly trunk will leave the room looking uncomfortable. 

The best way your rubber plant can survive such a disaster is to prevent it from happening in the first place. This brings us to the question—how can you tell if your rubber plant is underwatered? 

There are four basic signs that indicate your rubber plant is under-watered. Probably the first sign you’d notice is the yellowing around the edges of the leaves. The next sign is the drying of the tips which comes right before complete drooping or shedding of the leaves as well. Another clear indication can be noticed from the soil, as it could be too dry for sustaining or reviving plant life. 

In this article, I’m going to put you through how to detect the signs, how to detect the cause, how to respond to each of the major causes, and what’s the overall best method of reviving your rubber plant from further deterioration. 

Let’s start with answering a simple question to put things in perspective…

Why does a Rubber plant get dehydrated?

Indoor potted Rubber Plant underwatering Signs

Rate of Watering 

A midrange (neither succulent nor thin leaves) plant such as the ficus elastica is quite easy to water. As the plant is a rainforest variant that thrives on less water and low altitude.

So underwatering is somewhat the best move. But most owners tend to abandon the plant because of its heavily spaced watering session.

Changing Seasons

Even though the water demands of your indoor rubber plant may be low, it still gets heavily affected by the weather conditions. For instance, spring and summer are the appropriate time to water your rubber plant once every 4 or 5 days.

As moisture tends to escape the soil a lot faster. But during winter and autumn, moisture tends to stay in the soil. Thus allowing your rubber plant to go a week or two without being watered. 

One who isn’t aware of this obviously won’t have a plan to handle the seasonal change issue. The result is usually starvation (Underwatering) or Overwatering.

Plant Size

Rubber plants 3-4 feet high require more water, as they don’t have the body mass to retain enough for their growth. This is why they’re watered at a shorter time interval compared to the adult rubber plant (6-10ft tall) which can take up to 2 weeks without water.

So it’s more likely for a young ficus elastica to get damaged from underwatering. All because of the shorter watering interval which can be neglected if the owner isn’t so free to foster the young plant. 

Type of Pot 

Apart from the soil, the pot in which you put the plant is quite important. How? There are two common types of pot materials which include ceramic and concrete.

The concrete pot is a porous option because the concrete material causes the water to leave the soil faster than a ceramic or glass pot would. 

So in the long run, rubber plants in concrete pots tend to have a shorter watering schedule due to the porous nature of the concrete material.

For instance, instead of a 5-day watering interval during the summer, you get 3 to 4. Which can be very strenuous for busy owners that might end up abandoning the chore. And thus risk the plant being under-watered.

Humidity Level 

Rubber plants originate from rainforests where it is very humid due to all the neighboring luscious green in the surroundings. If it’s a less humid environment like the office or an enclosed room, it can be very hard for the rubber plant to retain water. 

So if the rubber plant isn’t regularly watered in response to such a condition, the plant would most likely suffer Underwatering.

Room Temperature

Heat causes transpiration in plants which is natural, but too much of it can affect their growth. It’s the same with ficus elastica.

Even though it can still stand a significant level of high temperature, it’s bound to suffer if such a condition lasts for a longer time. 

As it can lead to severe damage by under-watering. This is a result of the plant’s lack of ability to sustain itself concerning excess heat.

For instance, the rubber plant can handle between 60-85°F(15-28°C). There will be an increase in its water demand as the temperature soars up. 

Dry Soil 

Another reason why rubber plants get dehydrated is due to the overly dry soil. Such soil has both the top level and the lower level dry (the soil should feel dry with no sign of moisture).

At this point, you should water your rubber plant, because failure to do so will result in dehydration. Signs that indicate dry soil is yellowing on the leaves and drying tips. 

This is just the plant sacrificing some of its parts to keep other crucial parts alive. All because there isn’t enough moisture in the soil. 

Signs of Underwatered Rubber Plant 

There are various ways you can tell if your rubber plant needs a glass of water or two. Knowing this narrows down the steps on how you can save or properly revive your rubber plant. 

Take note of the following signs and how they come about carefully:

Rubber Plant Drooping 

After watering the plant, water along with essential nutrients flow through the roots to the branches and then onto the leaves.

But when the plant does not enjoy an adequate supply of water, the parts of the plant begin to weaken. And it starts from the parts that get to enjoy the nutrient flow last, which is usually the tip of the leaves. 

For the whole plant to be drooping, then it is at a severe stage of being Underwatered. As the leaves will dry up and fall.

Rubber Plants have Brown Tips 

Apart from the absence of light, the rubber plant tends to get brown due to a lack of ample water. So the plant to maintain its sustainability sacrifices a leaf to keep the healthier leaves healthy.

Brown and Dry Leaf Edges 

This is a case of watering which could be caused by quick-draining soil. Such soil can be as a result of harsh weather conditions such as high room temperature, poor soil composition, or the pot in use happens to be too porous (like the concrete pot).

Leaves Turning Yellow

Yellowing of the leaves is more of a universal indicator of improper water supply to the plant. So It applies to both Overwatering and Underwatering.

Rubber plant leaves turning yellow due to underwatering

But in terms of underwatering, the symptom is due to less or no supply of water to utilize nutrients. Which could also lead to nutrient deficiency. 

Overall, the plant could be forced to sacrifice parts of its body to ensure sustenance. And yellowing of the leaves is the result. As well as just the start of it.

Rubber Plant Leaves Curling

When the leaves curl up, it means they’re getting nutrients, but not in the appropriate proportion. As you may be punctual with your watering schedule but you might not be consistent. Especially in the manner in which you’re supposed to water the plant. 

For instance, you might only water the plant to the point it doesn’t pass the top level. And there could be other times where you did.

This inconsistency in conjunction with seasons that require less watering or more watering results in an Improper water supply. Thus, causing the leaves to curl up.

Dry Brown Spots on the Leaves 

Just as the appearance of brown spots is a result of over-watering, it can as well be due to under-watering. After, both over-watering and under-watering are cases of Improper distribution of water to the plant. 

So, instead of the root rot due to excess water, the problem could stem from a weak and Brittle root with less access to ample water. 

Potting Soil is Dry 

Another sign of underwatering can be seen from the soil, as it could be fast draining. The reason for this can be poor soil composition that doesn’t retain enough water in enough time.

Another possible reason is the material of the pot such as concrete. Which is quite porous, as it accelerates draining of the potting soil.

Brittle Roots 

After uprooting your rubber plant for repotting, you notice the roots aren’t flexible but rather easily breakable. This is due to the lack of water in the soil.

Is my Rubber Plant under or over-watered? 

Various signs can be indicated for both over-watering and under-watering. So it’s very easy to mistake one for the other, and that can be detrimental to the revival of your rubber plant. 

Below is a table showing the clear difference between under-watering and Overwatering:

Underwatering Overwatering 
Rubber leaves get really dry before droopingBrown color starts to develop on the leaves
The roots become brittleThe roots swell and rot
Soil becomes completely dried outYellowing develops on the leaves due to water-logged soil 
Stunted growth Root rot, gives a bad smell, attracts pests, and diseases 
Curled leaves Yellowing leaves
Crisp stemsMushy, fat stems
No smellSoils smells
Fungus and mold absentPresent 

Identifying the Causes of Underwatering 

Irregular watering 

This is one of the major causes of Under Watering in rubber plants. An Improper supply of water can negatively affect the plant’s roots. Especially when factors like change in season, level of humidity, harsh temperatures, and so on come into play. 

For instance, you can’t water your plant in the same manner as you would in summer when it’s winter. Because the soil during the winter tends to retain more water than the soil in the summer.

And if it’s scorching hot(high room temperature) then there’s going to be a lot of watering because transpiration is accelerated. 

Solution 

You need to set up a watering plan that is both good for your schedule and your plant. This should be done with several factors such as temperature change, seasonal change, the biomass of plants, and other factors as I explained earlier in this article. Doing this will provide you with the appropriate timing for watering your plant properly.

Poor Soil Water Holding Capacity 

Apart from Irregular watering, the problem of underwatering could also result from the soil’s ability to retain water, which could be poor. There are two reasons for this problem. It could either be due to the soil composition in the pot, or the material of the pot.

In terms of soil composition, the soil can lose its nutrients along with its ability to retain water for a  longer period. The pot holding the soil can also be a problem if the wrong material is utilized. A concrete pot is very porous (low water is retained). 

Solution 

The best solution is to report your plant with better soil composition. And the pot should be made out of a material that helps to retain water. Like clay or glass for example. Not concrete.

Nitrogen Toxicity 

Nitrogen is one of the most essential nutrients every plant needs to improve its growth rate (to increase biomass). It’s too much of it that becomes very toxic, not only on the nutrient level but also the biomass or structure of the plant as a whole.

And the reason for this claim is because excess Nitrogen will increase the number of leaves, stems, and stalks on the plant. 

But this growth won’t balance out with the plant’s rooting system. Thus creating an unbalanced plant that has a rooting system that cannot meet demands as a regular rubber plant rooting system would for a regular rubber plant structure.

Solution

Instead of risking Overwatering your plant by adding more water to neutralize the excess Nitrogen, the best option would be to re-pot it. And it should be done with better soil composition and the new fertilizer should be applied appropriately.

Fast Water Evaporation 

Another reason why your rubber plant is under-watered could be the rapid evaporation that takes place due to an increase in room temperature. Although the rubber plant may do well at withstanding heat, it still has a breaking point. 

For instance, the rubber plant can handle temperatures between 60-85°F(15-28°C). Any figure higher than that will cause uncontrollable transpiration, which can lead to Underwatering. 

Solution 

Keep your potted plant in a warm room, where transpiration is controlled.

How to Revive your Underwatered Rubber Plant 

Here are steps on how you save your rubber plant from under-watering:

Cut off Severely Affected Parts

When you discover browning on the leaves or the stems of your rubber plant, cut it off immediately. To prevent the spread of the illness to other healthier parts of your rubber plant.

Using Proper Potting Mix

This action should be considered only if repotting the plant is necessary. And a balanced soil mix should be set up for better growth and welfare of your rubber plant.

Choose Right Size of Container

Picking the right size of pot for your plant helps with convenience. A larger one will retain more water than a smaller one, but it would require heavy watering which could risk over-watering and under-watering. 

A smaller pot on the other hand requires light watering, but there are shorter days between each watering session, which could affect your busy schedule. 

Place The Pot in a Suitable Environment

The best way to avoid under-watering is to place your potted rubber plant in an environment that’s least affected by changes in season and temperature. That way, how you water the plant would remain somewhat uniform and easier to follow.

Follow Watering Regimen

Once you’ve set up a plan with all the factors involved (such as seasonal change, room temperature, and so on) you should stick to it. As it’ll prevent any mishap like Over-watering or under-watering from occurring.

But right before watering, make sure to perform the moisture test on the soil. 

Moisture test:

  • Make use of a stick or your index finger to dig 2-3 inches below soil level
  • Then rub fingers to detect moisture 

Note: If you detect moisture, then it’s not appropriate to water your plant.

How Often to the Water Rubber Plant 

The rate at which you water your rubber plant should be decided with some factors in mind. Factors such as the current season, room temperature, room humidity level, pot type, and plant size as well. 

Here’s a helpful scenario: a younger rubber plant during the summer or spring will require consistent watering in between shorter days (4-5days) because it’s a smaller plant (2-4feet).

As its biomass can’t retain enough water to be sustainable. Unless it’s present among other indoor floras which offer a more humid atmosphere collectively. 

As for an Older healthier rubber plant (6-10 feet) during the winter or autumn season can last for quite a long time without watering (1-2weeks). Mainly because the winter and autumn season is favorable for water retention in soil.

Note: before watering your rubber plant, dip up the soil and test for any sign of moisture. Once you’ve detected moisture, then it’s not ideal to water the plant. Unless it’s all dry.

Final Words 

The rubber plant is one of the easiest to care for when you consider its basic demands and resilient nature. But its ever-changing nature makes the game a lot harder.

In this article, I’ve provided you with all the basics that should guide you into preventing your rubber tree from damage due to Underwatering. 

So when the problem does arise you’ll know why it’s happening, signs that show it’s happening, what are the causes, and which method is best for reviving your rubber plant. 

Arifur Rahman

I'm the owner of gardenforindoor.com. After completing my bachelor of science in agriculture, I'm serving as a civil service officer at the Department of Agricultural Extension, Bangladesh. I started Garden For Indoor to make your indoor gardening journey easy and enjoyable.

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