Lately, on various Hoya forums, I’m seeing a lot of interest in an athletic field ammendment called Turface for growing Hoyas. Here are a couple of words of warning about my experiences with it. Also, thrown in is my experience growing Hoya multiflora in semi-hydroponics.
I should probably not say anything, but I can’t help myself. Here is my experience with both multiflora and Turface. Multiflora grows like a weed for me when grown conventionally in a moist, loose, peat-based mix. For fun, I tried growing it in semi-hydro with hydroton; it grew one leaf, flowered once, stalled out, and quit growing while the multiflora growing in regular mix tripled in size. The plant in semi-hydro eventually went downhill, and I threw it out. All I will say about Turface is that I bought six bags (300lbs) of it, and I have since spread it on my driveway. The biggest problem with Turface is that it is heavy, and it keeps the plants too wet. I once rotted the roots off from 15-20 plants using it. That is my experience with Turface, and my word of warning. Your results could be different, but proceed slowly with this product.