Add a 1/2 cup of copper to a Rubber tree plant soil what Will the out come be?
Copper compounds are usually used to increase soil acidity. If your rubber tree is a Ficus elastica, it will be happier in a neutral to slightly caustic pH. If you've already added it, no need to do anything however, as it is practically impossible to permanently change the pH of a soil, and it will return to the original in time as normal watering will flush out the copper. If you haven't added it yet, don't.
It is possible to overdose easily with copper, which would kill the plant. Depending on which copper compound you are using and the size of the plant's trunk and root system, half a cup of copper may be too much. Copper sulfate is used for fungus control.
