My rubber plant has grown too large to carry in and out of the house for overwintering, so I've built a small EasyStart greenhouse around it where it stood on the back porch. It's been there a couple of weeks, and it seems some of the leaves are curling. I don't see any webs except for those of real spiders - not mites. One of the leaves curled tightly and a portion of it turned black on the backside. It's hard to tell from that tiny Hardiness Zone Map but I think I'm in zone 6b or 7a. The question is: am I killing my decades old plant?
unless the greenhouse is heated, it's not warm enough for this plant. if it's too tall to bring in the doorway, you can top it off and root the upper part - either in the same pot as the main plant or in another one.
Curled, blackened leaves are a sign of cold damage.... Here in NY, it's been way too cold outdoors for plants (especially at night) if you don't have ANY heat for your plant, it needs to come inside. For plants to be safe and comfortable, they like around the same temps as us humans. New leaves will sprout later around the area (s) where you made any cuts, so don't be afraid to cut it back some.