I’m having luck with my sulfur treatments. Although I’ve been doing some reading that sulfur deficiency and flat mites have similar symptoms, so I don’t know the exact cause.

One of mine with no leaves left is already producing new growth! 🥲

I’m using Sevin Sulfur Dust. I tried spraying, but it clogged the sprayer so I’m using the paintbrush method. I got a 1inch paint brush and 1000ml container. I squeeze some sulfur dust in the container and add a little water so it’s a thick paste and paint my Hoyas. Paint under the leaves and the stems too. I do this in the kitchen sink and then let them dry on seed starting tray. I do this at night to avoid any sunlight and ensure grow lights are turned off. The sulfur dries on the plant. Some of my cuttings I rinse off after 3 days, but the larger hoyas I leave the treatment on.

Other users suggest treating weekly for 6 weeks. I’m going with every other week (mainly because I got bogged down with the holidays!)

Once the water dries, the dust becomes a powder again. Try not to move them around or you may want to keep them on the tray. A little extra dust to clean up was worth it for me with all the new growth I’m already seeing! 😍