Hi lightning....according to David Liddle, most hoyas grow in a somewhat acidic medium. However, you're right, the eriostemmas seem to grow and bloom much better with lime added to the potting medium. Many growers, myself included, add pellitized lime to the potting medium...and use this for all plants. You may wish to also add charcoal to your mix....lime and charcoal are commonly added...it prevents the mix from getting "sour". Just be careful to not over do it. You can either mix it into the mix, or sprinkle a teaspoon on the surface of a 6-inch pot. Some people have tremendously great results doing this, however, I haven't really noticed a difference so far. Hope this helps. Fondly, Patrick

I do the same. I add a small amount of Dolomitic Lime to provide Calcium to my soil mixes.
The ratio is 1 Tablespoon per gallon of mix. The pH will raise slightly, but that's fine if
you're using an acidic medium such as peat or bark.

Josh

Josh, do you do that for all your hoyas, not just eriostemmas?

Patrick, I didn't know that most hoyas prefer slightly acidic---thanks for passing along that information, and about charcoal too.

I do that for all my plants, whether Hoya, Citrus, Maple, Pepper, Pine, Orchid, or Jade.

Josh

I also use the garden pelletized lime on most of my hoyas and will eventually add them to the ones that I will be repotting in the near future. One of my main ingredients in my potting mix is small pieces of Pine bark or fir bark.

I add gypsum for the gritty mix for my non hoya plants.