My tropicopia's leaves are very sticky. What can I do?
This is a symptom of a pest infestation. It could be one of several pests (aphids, scale, whitefly, etc) who secrete honeydew which makes the leaves sticky.
Fortunately, all of the possible pests are treated the same. A general pesticide will take care of them. I personally like neem oil. Here is more information on it:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm