Last year was my first with Hoyas, so when the time came, I moved them inside so that I could enjoy them. It wasn't long before I noticed the leaves begin to yellow and drop off. I decided to make a change to the greenhouse where the air is much more humid and gets brighter light. That made all the difference. New leaves began to appear and it developed peduncles. From that experience, I believe they do not like the dry air in the house during my winter. This year they go straight to the greenhouse!
Beverly

Hoyas can respond like that to change and then come good again. And carnosa can take quite a lot of sum. My father had a large one that was in full sun and it flowered prolifically. But they do like their humidity, which is usually in short supply in a house.

Thanks folks, I shall give it a wee spray now and again to up its humidity. I cant keep it in the greenhouse unfortunately because I dont heat it over the winter months (costs are too high). Once again very many thanks I shall see how it gets on
Rgds
Averil

Misting plants only increases humidity momentarily. After that, the water left on the leaves just increases chances of fungal growth, especially indoors where there is usually little to no air movement. The only way to create a lasting effect is to use a humidifier to increase the humidity of the entire room/house. Localized humidity simply disperses into the surrounding air too quickly to be of any use to plants.

While humidity could be an issue, but my first suspicion is always the roots/soil. Check whether the soil is drying out in a reasonable time, and check on root growth however you can (peek in drainage holes, dig a little, or even slide the root ball out of the pot). If you don't see numerous white roots you should probably consider repotting into a more porous soil. At the very least, make sure your plant is not being overwatered since it will use less water indoors.

-Chris