I've been trying to figure out the problem with my rubber plant and bird of paradise by scouring the web and even taking them to the nursery. But they still seem to not be doing well. I received these plants about 4 months ago from somebody who was moving to another country. They have been next to huge west facing windows for the last 4 months. But I live in Seattle and in the winter you only get partial sun for about 8 hours a day. 2 months ago I put the bird of paradise in a tray with pebbles and water so the water would evaporate to create some humidity. I also started misting both plants 3-4 times a week. I use the Planta app to guide my watering and I make sure the soil feels moist, not too dry or soggy. But the bird of paradise's leaves still look very dry. And the rubber plant has had lots of new growth but has blackish-brown spots and a leaf that turned maroon and fell off. It's in a self watering container. They are the only tropical plants in the space and are about 5 feet from each other. The other houseplants in the space - aloe, spider plant, and compact dragon tree - are doing just fine.