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Rubber Plant or Rubber Fig leaves may turn brown due to a number of reasons which include improper watering, pests, root-rot, high temperatures, insufficient light, improper feeding among others.
Brown leaves in Rubber Plant are an indication that the growing conditions are not right. Below we have discussed 11 causes of brown leaves in Rubber Fig. Keep on reading for more on these causes and how to fix them.
Overwatering a Rubber Plant leads to soggy soil (excess water in the soil). Too much water in the soil reduces the oxygen concentration in the rootzone and this causes the roots to die due to root-rot.
When roots die, they cannot take up water to the leaves, they wilt due to dehydration, turn brown and die.
Carefully slip the plant out of its pot and inspect the roots. Brown-black mushy roots indicate root-rot, trim them off and treat the healthy roots with a fungicidal solution.
Disinfect the pot with the fungicidal solution or use a fresh pot to repot the plant in fresh free-draining soil.
Do not water the Rubber Fig and keep it dry for some time before resuming watering. Read more on how to treat root-rot here.
To avoid getting soggy soil, ensure that the pot for Rubber Fig has a drainage hole and the soil is free-draining.
Allow the top 2-3 in. of soil to dry out between waterings and cut down on watering during the cold season to maintain the soil slightly moist as growth is minimal at this time.
Underwatering means that there is too little moisture in the soil. As such, the Rubber Plant cannot take up nutrients and water to the leaves. Therefore, they wilt, turn brown and die.
Water the Rubber Fig liberally during the growing season until it comes out through the drainage holes while allowing the top 2-3 in. of soil to dry out between waterings.
Reduce watering during the cold season but do not let the soil dry out completely, maintain the soil slightly moist.
Rubber Plant is prone to spider mites, aphids, scale insects and mealy bugs which attack the new growth from where they suck the plant sap.
This causes the plant to become dehydrated and results in the leaves wilting and browning.
Regularly inspect the Rubber Fig for the pests and take timely control measures.
Treat the Rubber Plant appropriately for the pests with appropriate products like neem oil or insecticidal soap among others.
Rubber Plants require average room temperatures within the range of 15-280C for optimum growth.
Extremely hot temperatures above the optimum range will cause dehydration of the leaves resulting in wilting, browning and eventually dropping.
Keep the Rubber Plant away from hot drafts like hot surfaces, hot air vents and other hot areas to prevent extremely high temperatures.
Maintain an average room temperature within the range of 15-280C. Usually, a room temperature that is comfortable for you is ideal for the plant.
The Rubber Plant requires bright light with some direct sunshine to thrive. The light is needed for making food that is required for energy and growth.
If the light is insufficient the plant cannot make enough food for energy and growth. In an attempt to save energy, the plant begins to die from the leaves. They turn yellow, brown and eventuall die.
Move Rubber Plant to a brighter spot where it will receive bright light with some direct sunshine or instal a grow light if natural light in your home is not adequate.
Occasionally rotate the pot to ensure that the plant absorbs enough light for photosynthesis on all sides.
Overfeeding Rubber Plant will cause the roots to die due to fertilizer burn. When the roots die, they cannot take up water to the leaves.
Without adequate water, the leaves get dehydrated, they wilt, turn brown and die.
Take care not to overfeed the plant. Feed Rubber Plant during the growing season with a balanced, water-soluble fertilizer and follow the instructions on the label of the plant food to avoid overfeeding.
Do not feed the Rubber Fig during the cold season as growth is minimal at this time and feeding at this time can lead to fertilizer burn.
Flush out the salts from the soil regularly by running a stream of water through the soil until it comes out through the drainage holes and repeat the process several times.
Underfeeding implies that the Rubber Plant is not getting enough nutrients need for growth and energy.
Inadequate nutrients in the actively growing tips causes nutrients to be withdrawn from the older lower leaves which turn yellow, brown and drop.
Feed Rubber Fig during the growing period with a balanced, water-soluble fertilizer and follow the instructions on the label of the plant food to avoid underfeeding.
If a Rubber Plant is root-bound, the roots have filled the pot and there is very little soil to hold water when you water the plant.
Therefore, there is no water for the plant to take up to the leaves. The leaves loss their stiffness and they wilt, turn brown and drop.
Check the bottom of the pot for roots growing through the drainage hole and repot the Rubber Fig into a pot one size larger than the current one.
Repotting may cause a Rubber Plant some shock which may lead to some leaves wilting, turning brown and dropping before it can adjust to the new growing conditions.
To minimize repotting shock, water the Rubber Fig thoroughly one day before repotting. A well hydrated plant experiences less shock.
Do not make too many changes at once. For instance, after repotting, maintain the Rubber Plant in the same location until it is well established before moving it to a new location.
As the Rubber Plant matures, it loses the lower leaves leaving a bare stem with a crown of leaves at the top. The leaves turn yellow, then brown and eventually drop.
Cut back the Rubber Fig stem at the desired height to rejuvenate growth. New growth should sprout just below the cut into a new bushy plant.
Poor quality soil does not drain easily and therefore it easily becomes compacted or soggy which can negatively impact the growth of the Rubber Plant.
Rubber Plant requires loose, free-draining soil that does not hold excessive amounts of water as soggy soil can lead to root-rot disease which is characterized by yellowing, browning and dropping leaves.
Pot the Rubber Fig in good quality soil that is loose, free-draining and rich in organic matter like this quality potting mix on Amazon.