F. Elastica is among the oldest plants used as houseplants worldwide. Elastica leaves and stems and even wood 'bleed' white sticky sap when broken or damaged from which rubber can be made. Some people are allergic to this sap when applied to the skin. As a houseplant, Ficus is very popular. Able to adapt to and endure lower light conditions and generally poor treatment, The Rubber Tree is a winner indoors. Provide as much light as possible, keep away from cold and drafts in winter, keep soil lightly to moderately moist with good drainage. Most any soil will be fine and largely sandy soils mixed with some organics are ideal. Frost Tolerance: Some foliage damage below 30F. Propagation: Air layering.