How to make the trunk of a rubber tree stronger
I have a rubber tree that has grown to about 5 ft tall. The new leaves continue to get bigger and bigger as they unfold and the trunk, which is only about 1-2 inches in diameter, cannot hold the tree upright. I currently have the tree tied to a bamboo stick to hold it up. I was wondering if there is anything I can do to make the trunk stronger and/or thicker?
There are a couple of things. The first involves cutting back the plant. Prune the trunk down to, maybe, 12 - 18", and let it make new leaves. You can stick the cut end, shortened somewhat to a look you like, into soil where it will probably root. The second thing is wait until spring (unless you live in zone 9 - 11) and let it live outside under some trees for shade, where the wind can blow it. The movement of the trunk will thicken and strengthen it. Much like muscles. This article has some more general info on rubber trees: https://www.gardeningknowhow.com/houseplants/rubber-tree/how-to-care-for-a-rubber-tree-plant.htm