Hi! First time posting.
I've been raising my original Hoya for more than twenty years and I've never seen this! I've inspected the plants for any bugs or mites and don't see anything.
Could someone help me determine what's happening here and how to treat my plant?

I may be wrong, but IMO I think that looks like a fungus or a rot of some sort. Maybe someone else will weigh in. If that were my plant, I would immediately treat it with Captan. Captan is a wettable powdered fungicide that you mix into a slurry and put on with a tool like a spoon. Home Depot and Lowes used to have it but I don't know if they still do. It does;t look like bugs to me.

It does not look like insect damage to me either but rather appears to be a bacterial or fungal issue. I'd remove the heavily damaged leaves and use a fungicide to try to get it under control on the plant. If you don't have fungicide on hand, ground cinnamon is a natural bactericide/fungicide. I keep a container of cinnamon with my garden supplies, just for use on plants. Sprinkle it on the affected areas.

Thank you so much for the help! I'll try to find the Captan and start with that. I'm very attached to this plant and don't want to lose it!

Thankyou, I have a few black spots starting on some rigida lvs. might be from obovata dripping on it from above it. But I'm going to try fungicide I think. :thankyou.

I know this thread is a couple of years old but I have purchased this plant twice and I love it but both times some of the leaves turned yellow and then fell off but mostly they all got black spots on them. I'll treat it with some sort of fungicide because that appears the right thing to do but what am I doing wrong that this keeps happening?

Hi Pansy58,

Fungal issues usually arise in moist, humid conditions and where there isn't adequate air flow. For indoor plants (especially if they are grouped together) it's a good idea to occasionally have a fan running to help keep the air circulating.

Hoyas require a chunky potting mixture that allows for good aeration at root level and adequate drainage. I'm in hot, humid Florida where my Hoyas stay outside year round. Even though my plants are growing in a fast draining potting media (a mixture of mostly orchid bark and perlite with potting soil added) which allows the roots to dry quickly, there are times in summer when we get lots of rain and the air is very still and my plants will still have a leaf or two with fungus. I remove any affected leaves and sprinkle the plants with cinnamon powder which acts as a natural fungicide. Thankfully, the breezes return quickly and I've never lost any plants to fungus taking over.

Hi purpleiris757
Did you manage to save your queen??
I have the same problem!
Black spots on the leafs and every leaf turns yellow and die.
Tried to take all the badly damaged and it keeps on dying.
I'm lost, considering to try and root a cutting. Due the condition i will have to butcher the plant to get 3 undamaged leafs.
Helpppp

Hi VeronicaPeretz, to garden.org!

This thread is over 2 years old and it looks like it's the one and only time that Purpleiris757 ever posted, so she may not see your reply.

That being said, yellowing, dying leaves can be a sign of over watering as well as under watering but black spots on the leaves sounds like either a bacterial or fungal issue that may have begun at root level. How is your plant potted, does the container have drainage holes, what type of soil are you using? Can you upload a photo or two of your Krimson Queen Hoya (Hoya carnosa 'Tricolor'), showing it's pot and soil? Photos will help in diagnosing the exact issue and allowing us to offer advice.