Q.Houseplants exposed to 40 degree indoor temp
Hello, I returned from a 5 day trip and found that our furnace was not working. The indoor temp was 40 degrees! I lost a number of houseplants, but my hibiscus plants have almost no leaves on them, and appear to be infested with aphids. I already have cut them back by 1/3, showered them, and applied insecticidal granules to the soil. It’s a long time until June; is there any hope? Thanks

Certified GKH Gardening Expert
You do not want to prune hibiscus until right before you put them out for spring. It is common for one to lose its leaves indoors anyways. The lack of humidity forces it into a semi dormant state. The only thing you can do now is water it when it is bone dry only, and wait until you can put it outside. It is very possible that it will not survive with the early pruning, but anything that can be done will be on its own.
Here is an article for more information: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/tips-for-pruning-hibiscus-plants-when-to-prune-hibiscus.htm