An acid (like vinegar) will dissolve the deposits. I would use straight vinegar since it has never harmed any of my plants, and will still require several applications to remove heavy deposits. Diluting the vinegar will just make the process that much longer. It would be best to wait until the plant is dry before doing this so that you can thoroughly water it afterwards in order to flush away any excess vinegar that may be on the foliage and soil.

Also, I would stop misting the plants. Misting only momentarily increases humidity, and the water left on the foliage can cause fungal growth and the hard water deposits you are seeing.

-Chris

My grandma used to shine her leaves with diluted milk. I only ever see these spots on new plants. Something they put on them seems to make them spotty. These plants are usually also waxy and dull. Rubbing them while they're wet, then rinsing them off can help. After a few times in the rain they look better.

I don't know about using vinegar. There's all kind of hullaballo about using it to kill weeds. We need a scientist.

Straight vinegar is a pretty good herbicide, too, so watch it! Personally, I'd like to see you use a wet, soft cloth...perhaps with a diluted vinegar solution. Place one hand behind each leaf to cushion and support it, then gently rub the surface tip clean.

Leaf shine products can sometimes be sticky, attracting dirt and dust. Plus, you still have to get the spots off. I strongly agree with the recommendation that you stop with the daily misting. It rarely offers any true benefits and can sometimes cause problems. As I recall from your other posts, you are a bit of an 'over-nuturer'...stopping might not be easy for you, lol!

I should clarify that straight vinegar applied to the leaves of my plants has never harmed them. If applied to the soil, that's another matter. I rub the leaves with a paper towel soaked in vinegar. They will look clean as soon as they are wet, but once dry, any remaining deposits will show themselves again. Keep reapplying vinegar and wiping until the leaves remain clean when dry. You can rinse with water when done, and you should flush the pot thoroughly if any vinegar (diluted or not) has gotten in the soil.

-Chris

thanks all. Hummm not mist my plants-- I won't have a reason to wake up!! lol. Oh wait, I have a DOG!!LOL! But ok, I will stop the misting, I mainly like the way they look wet, clean and fresh-- :) Til they dry and I see spots on them. Can't win for losing.

and I do kinda over-nuture them I guess. I am trying to give them some space-- and yes, it is hard. lol

But thanks again
Marjie

Not sure if this is appropriate for Hoyas, but rainwater naturally has a slightly acidic pH - I put my large-leaved plants (F. elastica, Dracaenas, Monstera) outside in the rain this time of year, when it's above 50* and raining, to wash the dust off & I don't notice spotting. I put the small-leaved ones out there too ;)

GB

Marjie - Other than the leaf spots from hard water, there is no harm in misting. My primary point was that misting has no real benefit horticulturally. But if it gives you a reason to get up in the morning, then by all means do it! YOu could alos try misting with filtered or distilled water.

~Will