You are reading this article because have a rubber plant whose leaves are drooping and you want to revive it. Whatever your reason, you have come to the right place.
Your rubber plant’s leaves will be drooping because it is not in conditions suitable for it. Rubber plants are at home in tropical forests and so need tropical conditions resembling their natural environment. Drooping is a sign of unsuitable growing conditions.
I will walk you through the causes of rubber plant leaves drooping and solutions to each of them.
Causes of Rubber Plant Leaves Drooping
Temperature Too Low
If you keep tropical plants it is a good idea to have a thermometer in the room where the plants are. Rubber plants thrive in temperatures of 16-24 °C (60-77° F) but leaves will droop if temperatures below 10-12° C (48-50° F)
Pressure, volume, and temperature of fluid [e.g. water] are all related, so as temperature drops, so does water pressure. Below 10-12° C (48-50° F) pressure drops too low to keep the rubber plant leaves firm, so they droop.
Sometimes the floor on which the plant pot stands is cooler than the ambient air, and this causes the plant to become too cold. This is especially the case if outside temperatures are cold. Contact with the floor cools down the plant. Placing the pot on a mat is a good idea.
Also, a window can be too cold a spot. Windows can be very cold at night, especially in cool seasons, and this can cause drooping.
Windows that are not double-glazed are notoriously cold, especially at nights and in cooler times of the year. But even double-glazed windows can be chilly, especially in winter.
I listed down some facts and rubber plant requirements that will help you maintain the temperature and humidity at your location:
|USDA plant hardiness zones||10b-11|
|Maximum Temperatures||75 to 80 degrees Fahrenheit|
|Minimum Temperatures||40 degrees Fahrenheit|
|Humidity||Near about 40 percent|
- You need to ensure that the thermostat is set so that the temperature never dips too low. Temperature maintenance is vital for tropical plants.
- Ensure that you measure the temperature around where you want to place your plant. Move plants to places where warmth can be ensured.
- Keep the plant away from the cold draft of the air cooler or window.
Cold Air Is Damaging
No matter how high your thermostat is set, a flow of cold air can be fatal to a rubber plant. Leaves will soon droop and may drop off. Cold air flows can occur in poorly insulated houses or where doors are often opened and worse left open.
- Ensure that there is no cold draft flowing into the room where the plant is kept. This is especially important in cooler times of the year.
- Airflow around the plant is vitally important for the prevention of fungal diseases like powdery mildew. so do not attempt to protect your rubber plant by keeping it in a confined area.
- Instead, ensure that warm air flows over it. All plants breathe carbon dioxide through their leaves to photosynthesize, and rubber plants are no exception. So a constantly renewed supply of air is required. But it should not chill the plant
Heat Stress Cause Rubber Leaves Drooping
It is a balancing act. Even tropical plants can tolerate overheat. When they overheat a major symptom is wilting. Leaves droop and the stem can become flaccid. This is due to the plant losing water faster than it is being replenished.
Plants lose water by transpiration from the leaves, and as temperatures rise the transpiration rate rises. When conditions are too hot for the particular species of plant it loses water too fast, because the transpiration rate is too high.
This causes lowered water pressure in the leaves, causing drooping. Rubber plants’ leaves will droop, even before the permanent wilting point is reached.
Major effects of heat stress on the rubber plant:
- Water loss
- Reduction of Physical growth
- Oxidative stress ( some sort of dysfunction in plant physiology)
- Improper development
- Alteration in photosynthesis
- Alteration in Rubber plant phenology (Timing of new leaf growth, flowering, dormancy, etc and other seasonal activities of your rubber plant)
- The remedy is to remove the plant from the excessive heat source and provide water.
- Keep the plant away from the direct heat source or sun exposure
Drooping leaves, or leaves that grow crisp before dropping off, are sometimes signs of insufficient humidity in the air. Rubber plants are adapted to the humid air of the tropical rainforest.
This means that when the air in a rubber plant’s environment is insufficiently humid. So, its leaves tend to dry out, as water moves into the air that is dry and can easily absorb it, making them droop. This is because plants lose water by evaporation through pores in their leaves.
As a tropical plant rubber plants love a humid environment 40-50% humidity will keep the plant healthy. If excess humidity is the cause, try to allow some air into the plant’s environment.
An alternative method is to fill a pebble tray with water and stand the plant pot on the tray, ensuring that the water does not touch the soil. This will ensure that a moist, humid environment is provided for the plant.
If still, humid air builds up around the plant the air can be saturated with moisture and so the plant cannot transpire as the saturated air cannot absorb any moisture. This causes a failure of necessary chemical processes in the leaves, causing drooping.
Lack of Nutrients in the Soil Causes Drooping
Plants feed on soil and so if the soil is inadequate the plant will suffer. The nutrient for leaves is nitrogen, but also phosphorus is necessary for general plant health.
As rubber plants grow naturally in tropical forest soils, which are not very rich, you do not need a very rich compost, an ordinary one will suffice.
However, you need to feed your rubber plants periodically with fertilizer. They should be fed once a month in the growing season, (Spring and Summer). Do not over-fertilize, as this can cause fertilizer scorch in plants.
I try to apply the half strength of the recommended guidelines, it will minimize the risk of overdose and fertilizer burn.
Overdose of fertilizer burns the root system and destroys the ability to absorb nutrients and water necessary for vigorous growth.
- Have a fertilizer schedule and stick to it. Once in a month and half of the recommended strength.
- If you are going away arrange for someone to tend your plants
- Do not fertilize in the Fall and Winter. This is the dormancy period for the plant.
Lack of Water Leads to Wilting
Watering is a fine balancing act. You can water too much or too little. Too little water causes plants to wilt. Too much can be damaging [see below]
Leaves keep their shape and texture because there is sufficient water inside them. So the loss of water makes leaves begin to lose the turgor pressure. As a result rubber plant leaves droop when they are not watered.
- Water when the top 1-2 inches of soil becomes dry.
- Use a well-draining but can retain necessary moisture content.
- To avoid leaves drooping, water the plant once a week in the growing season, ensuring that the soil is wet, but that there is no water pooling up on the soil’s surface. Ideally, the soil should be allowed to dry out slightly between watering sessions.
- Rainwater is better for plants than tap water is, as it is not chlorinated.
Waterlogging is a Plant Killer
More plants are killed by overwatering than by underwatering. You may kill your plant by being too kind. An overwatered rubber plant has leaves that turn yellow and mushy before they droop and fall.
An important symptom of overwatering is oedema [edema.] This is a build-up of small white spots [blisters] on leaves. If left untreated it leads to yellowing, drooping, and leaf loss.
Edema is caused by the plant’s roots taking in more water than the plant can lose by transpiration through its leaves. In effect, the leaves look droopy.
The remedy is to cut down water for a week until new healthy leaves spring up.
Plants take in oxygen via their roots.
They get it from air found in the spaces between soil particles. It follows that if these spaces become filled with water the plant cannot breathe. Its leaves droop and fall off. This is why flooding is so bad for plants.
One known cause of waterlogging is that some growers use a pot that is too large for the plant and then endeavors to fill it with a lot of water than necessary. Drooping of leaves is an initial symptom. Shriveled and crispy leaves are symptoms of underwatering.
- If for some reason your rubber plant suffers waterlogging it is possible to save it by re-potting the plant. Do so promptly. You will lose leaves, but you might save your plant.
- Alternatively, you might try to drain water from the soil.
- If you do this, using a garden fork [a small one] pierce the soil repeatedly to allow air into it.
- Here is an important piece of advice. Ensure that everyone with access to your rubber plant is fully aware of the importance of watering schedules.
- This is especially important when you have young children who may be tempted to water too much.
Light Levels Wrong
All plants need sunlight to photosynthesize and make vital nutrients, and rubber trees are no exception. But plants are adapted to different degrees of sunlight.
As tropical forest trees, rubber plants are adapted to conditions with some degree of shade. They grow up in the shade of larger trees.
For this reason, their leaves may suffer scorching if exposed to direct sunlight. Scorched leaves become damaged and so cannot function. This causes drooping.
Scorching occurs when leaves become dehydrated as excessive light takes photosynthesis and therefore transpiration to levels unsustainable for rubber plants.
One of the symptoms of scorching is small brown spots occurring on the leaves. These occur prior to drooping.
However, too little light is deadly, as the process of photosynthesis needs light, and the plant will die. You need to find the happy medium.
- Prevention is better than cure. Place your rubber plant where there is sunlight, but not direct light sunlight shining on it.
- If you have a glasshouse or similar structure invest in shading if you are putting your rubber plant there.
This is a common problem of potted plants. It occurs when the roots outgrow the pot. The roots start to wind around the sides of their pot.
This means that they have no room to grow and cannot spread to find nutrients and water. This means that they cannot function properly and growth is stalled.
- If your rubber plant seems to be outgrowing its pot, re-pot it in a larger container. You will lose leaves, but they should regrow.
- If you are repotting a plant, do not forget to fluff out the soil with your fingers to encourage the roots to spread out and grow.
Plants are not naturally mobile, and so they dislike being moved. Rubber plants show their dislike by shedding some leaves.
Rubber plants dislike sudden shocks, so sudden and large changes will cause leaf loss. The good news is that if the move is successful and is properly carried out, leaves will regrow.
When a plant is repotted transplant shock occurs. The root system of the plant can be damaged while moving.
As a result, it can not supply enough nutrients and water to the other parts of your rubber plant. You will see a droopy appearance just after moving to a new pot.
- Be careful not to hurt the roots while transplanting.
- Give few days to acclimatize to the new environment.
- Do not move the plant without a good reason.
- Make sure the new pot contains soil mixed with enough biofertilizer like compost to ensure the nutrient supply.
Rubber plants are vulnerable to specific types of pests. Some live on the leaves, but some dwell in soil and attack roots. Here are some common pests.
These hatch from eggs laid on leaves. Then they wander around the leaf until they find a feeding place. Then their limbs drop off and they fasten their jaws onto the leaf and begin to suck sap.
- Inspect leaves for these tiny creatures, which appear as little black spots
- You can wipe them off with a wet cloth
- They can be killed by an insecticide
- A jet of water from a spray gun also gets rid of them.
- Take off and burn any badly damaged leaves
If you find out any white cottony depository then your rubber plant might be attacked by the mealy bugs. These type of bugs sucks the juices out of the leaves and makes it look like droopy.
- Use cotton wool swabs dipped in alcohol to wipe the leaves. Repeat the treatment until the problem has gone.
- You may use neem oil instead of alcohol
- Mix one cup of rubbing alcohol with a few drops of liquid soap. Then spray the whole plant with it. Repeat the treatment weekly until the problem has gone.
Related to spiders the tell-tale sign of these almost microscopic creatures is yellow or brown spots on leaves and sometimes a set of webs.
- You need to keep checking for mites weekly
- If you spot their signs wash them off with a water jet.
- Spray the plant with neem oil
- If it is a serious infestation spray with insecticidal soap
Thrips and Aphids
These small, slender insects feed on plant leaves, flowers, and buds. They are able to fly. Symptoms are leaves that are pale and dirty-looking, and sometimes brown-striped.
Another sap-sucking insect is aphids which can vary in color from green to black. Heavy infestation causes the leaves and plants to droop and look unhappy.
- Wash them off with a strong water spray
- Neem oil and/or insecticidal soaps may be used.
- You may also use a hot pepper spray.
- These sprays must be used weekly until the problem has gone
- You may also use sticky traps, which are placed near the plant to lure these flying insects into them.
These very small creatures are like worms and live in the soil. The damage that they cause to plant rubber plant roots is stunting of the plant and yellowing of leaves.
- Take the plant from its pot.
- You should wash the roots clean with water
- Dispose of the old compost
- Mix a nematicide into fresh compost
- Repot the plant
- Water the plant well
Nematicides are pesticides developed for nematodes. They work when the soil has reached a certain degree of warmth, which is about 53-59 °F (12-15 °C)