The Lower Leaves Are Turning Yellow on a Rubber Tree

Overwatering

• Yellow lower leaves are a sign that your rubber plant may be sitting in waterlogged soil. Check that it is not sitting in a dish of water and that the drainage hole at the bottom of its container is not blocked. Only water your rubber tree when the top inch of its soil is completely dry. Make sure all excess water drains away.

Underwatering

• Water your rubber tree thoroughly, aiming to thoroughly soak the soil in its pot. Never allow the soil to dry out completely. A rubber tree that is receiving too little water will shed its lower leaves and may develop brown leaf tips and margins.

Soil Quality

• If you are watering your rubber plant correctly and it is still developing yellow leaves, it may be growing in poor quality soil that drains poorly. Repot your rubber tree using a potting compost made up of equal parts of peat, loam and sharp sand or perlite.

Low Light

• Move your rubber plant to a brighter location if its leaves are turning yellow and dropping off. Rubber plants thrive close to a south-facing or west-facing window that receives indirect sunshine. Bright light also increases transpiration and makes your rubber tree less likely to suffer from waterlogging.

Potassium Deficiency

• Rubber trees are vulnerable to potassium deficiency, according to the University of Florida IFAS Extension. Deficient plants develop pale margins on their lower leaves, which then die and drop off. Treat potassium deficiency with a product containing potassium chloride or potassium nitrate.

Other Causes

• Move you rubber plant away from doors and cold drafts and out of the airflow from heaters. Feed it with a liquid houseplant fertilizer once a month during the warmer months of the year and once every other month during the winter. Flush out the soil with abundant water every four to six months to remove excess fertilizer salts that can damage roots and cause leaf loss. Keep your rubber tree at a temperature range of 60 to 65 degrees Fahrenheit at night and 75 to 80 degrees during the day. Excessively high or low temperatures can cause leaf drop.