My hoyas will occationally get a strange or misshapen leaf or two and I don't worry about it. However, if it is an ongoing and regular happening on one plant, then I would suspect you may have spider mites. Do you ever find small webs around the leaves underneith? If so it is a good bet you do. You can use a spray for them or use a soil drench of Bayer Tree & Shrub to get rid of them. Follow the directions carefully on all insecticides you may use.
Marcy

...Or mealies - either leaf mealies or root mealies. Have you inspected the undersides of leaves and the leaf axils? If you find mealies, those may be your culprit. You have to unpot the plant to find root mealies, which look like white splotches on some of the roots, mostly towards the exterior of the pot. Get back to us and let us know what you find.

Denise in Omaha

Over fertilizing could create the same problem as well.
Leaves are smaller, misshapen, far apart and sometimes with brown or yellow spots.
It happend to me last summer when "plant sitter"- started adding her own stuff to my hoyas (full strength) at each watering to "help" with the blooms.
It supposed to be a surprise - lots of blooms.....she thought.

It only gets fertilized occasionally, with half-strength African Violet food. It has had leaf mealies, but I'm fairly certain I eradicated those quite some time ago-I haven't seen any of the cottony stuff for at least 6 mos. Root mealies, I don't know...but don't remember seeing anything unusual when I re-potted a year ago. And that was a major re-pot involving soaking all of the old dirt off...it was given to me by a friend 2 years ago in incredibly compacted soil...I didn't know much about plants at that point, and I left it in that soil, and kept it in too low of light until a year later when I finally learned some things about plants in general and hoyas in particular. At that same point I learned about mealy-bugs, and realized that the hoya had had them ever since I first laid eyes on it.

So this plant has been through a lot...I thought that it was doing incredibly well now considering everything, but now I know it STILL has a problem. It has also had spider mites before, and I thought I had eradicated them, but I just looked and saw that some webbing is back. I'm really tired of it at this point;I've never had so many issues with one plant, which I guess is due to the fact that it had major problems when I acquired it. I've had it away from my other plants for some time now, but I've now decided to put it outside and spray it with diluted alcohol twice a week (at night). If it still has "issues" by late Sept......it won't be coming back in.

That sounds like a good plan to me. When I have a problem plant, I give it the summer outside to get rid of the problem and if that doesn't do the trick, in the trash it goes. Sometimes plants are beyond help and I think it's good to know when to give up. I can't tell you how many times I've held onto a plant until there's absolutely no hope left and it makes me fell like such a failure. Yet logically, I know they all can't be saved. Right now, I have a Hoya polyneura that I'm struggling with. I should really just give it up and go buy a new one...

Denise in Omaha

Why does my hoya have these deformed leaves? Help!

For some reason my Australis does that too. I noticed it when I let it dry out too much. I'm thinking it was stressed, but truthfully, I don't have any real ideas. Maybe some others with more experience will chime in and offer up a reason.