Flat mites are becoming super common in the Hoya world, but because they’re so hard to see and do damage so slowly most people don’t know about them. A lot of cases of plants failing to thrive, never growing, or just looking sickly and slowly dying may be due to flat mites. You can see them easily with a cheap handheld magnifier, usually on the underside of leaves near the base.
Check out this link for more info: https://vermonthoyas.com/2022/11/09/lets-talk-about-the-new-hoya-scourge-the-flat-mite/
To cut to the chase, mix 2 tbs of sulfur with a gallon of water, shake vigorously, and put it in your sprayer. Shake frequently while spraying. Do it outside, we call it farting on our plants for a reason…
The gracilis (memoria?) pictured looked OK but it was next to patient zero, a fitchii that is just now coming back from the brink of death. The gracilis is suddenly growing like mad a month after farting. I left the sulfur residue on the leaves as a preventative so you can easily tell the new growth from old.
It pretty much kills the mites dead on contact, so I did everything once I understood the problem and all new plants will be doused, but unless I see mites on anything in the future I might make it an every coupla years thing. A few of my friends and I have a theory that sulfur is an important micronutrient for Hoya as we see bursts of growth on even plants that didn’t have mites.
Interesting! Thank you