A native of India, but now commonly grown as a houseplant, Ficus elastica or rubber tree requires little care to thrive. It is an evergreen and has thick, leathery leaves that have a glossy appearance. Its name comes from the sticky sap it exudes when cut. When the sap dries it becomes a similar substance to rubber. However, like all houseplants, Ficus elastica may experience a variety of problems over time.
The problem of dropped leaves on a Ficus elastica plant happens for several reasons. Both sudden temperature and light changes brought about by moving the plant disturb its growth. Areas with too little light or drafty spaces in front of windows or vents also cause leaves to drop. As they grow older, rubber trees naturally shed leaves from lower limbs of the plant.
Along with temperature change and age, overwatering often results in rubber tree leaves turning yellow and falling off. By choosing a pot with drainage holes in the bottom, you avoid the danger of letting your Ficus elastica sit in water. Constantly waterlogged soil also creates prime conditions for root rot in your plant.
Failing to transplant Ficus elastica when it outgrows its container results in stunted growth and root damage. However, when moving to a larger pot, go up only 1 inch in diameter as the plant requires some stability and likes to be slightly root-bound. However, if your rubber tree is in the midst of dropping leaves, wait to repot since repotting often makes the leaf dropping worse.
Oedema is a condition in which the roots take up water faster than the plant uses it; oedema causes water pressure to build up in the leaves. According to Cornell University, symptoms of this disease include small, "corky" blisters that form on leaves, petals and stems of infected plant. If the condition continues, leaves turn yellow and die as the plant becomes spindly. Oedema often occurs during winter when warm, wet soil coincides with cold, wet air, and water absorption increases. To prevent the problem of overabsorption, avoid overwatering Ficus elastica and maintain a low level of humidity during cooler months.
Powdery mildew is a fungus that affects Ficus elastica. It looks like unsightly, dusty, white spores that cover the leaves. At its worst, powdery mildew distorts leaves and growing tips on the affected plant and causes yellowing. To combat indoor powdery mildew, potassium bicarbonate and products with neem oil may prove helpful. Clean up any fallen leaves and debris from the soil around the infected plant.