This section is from the book "Indoor Gardening", by Eben E. Rexford. Also available from Amazon: Indoor Gardening.
This is the well-known and always popular Rubber Plant. It is one of the best of all plants for the amateur who desires something for the decoration of the hall in winter and the veranda in summer, as it can be grown much more easily than almost any other plant on the list. Its large foliage, thick and leathery in texture, with glossy surface and rich coloring, is always attractive. Give it a soil of good loam, a moderate amount of water, and plenty of light, and it will ask very little more of you. Its leaves can be washed as safely as a piece of crockery, and therefore it is an easy matter to keep them clean. When the plant is making vigorous growth apply a good fertilizer once a fortnight. If this is done it will not be found necessary to make use of very large pots.
If the foliage turns yellow there may be three causes for it: The plant may not get as much water as it ought to have-it may be root-bound-or the older leaves may be ripening, in which case it is the natural thing for them to drop off.
Sometimes scale attacks it. If any are found use kerosene emulsion.
Ficus pandurata is a variety of recent introduction. This has much larger foliage than Ficus elastica, the Rubber Plant, and soon develops into a plant of great dignity and beauty.
Ficus elastica variegata is a variety similar to the ordinary Rubber Plant in all respects but one. Its foliage is broadly and irregularly marked with light green and yellow. Very desirable by way of variety.