In the chapter on plant propagation we mentioned that seedling are often attacked by a disease known as “damping off.” As we said there, the use of a sterilized starting mixture has cut down the chances of this fungus affecting the seedlings grown in it. If, however, any of your seedlings are so affected, the only workable way to handle it is to throw away those attacked to keep the disease from spreading to the healthy plants.
Leaf mold is another scourge of house plants, especially of rubber plants and screw pines. The leaves which have become diseased should be removed and burned so as to keep the fungus from infecting the rest of the plant. If this remedy doesn’t work, then the only thing to do is to throw out the whole plant. If you let the condition continue for too long, other neighboring plants will catch the disease. This is probably the point for us to set down a general rule to be followed in all cases of serious blight or insect pest infestation. If one or several of your plants are badly affected, either by a fungus mold or by a heavy invasion of insects, the wisest thing to do is to throw the plant or plants away immediately. It is generally not worth the time, trouble and effort it takes to cure them, and every minute the diseased plants are in the house all your other plants are threatened.
There are times, of course, when this rule is very difficult to follow, especially with a plant you have had for some time and grown fond of, but no matter how much it hurts you to do it, destroying a badly infested or infected plant is the wisest precaution you can take for the health of your garden. If you have a comparatively mild case of rot or infestation in one of your favorite plants and you really want to save it, you should at least move it from its usual location and keep it isolated during its period of recuperation.