I am rethinking my thoughts about the light needed by hoyas after seeing how David Liddle grows his and learning more about them. I always thought that lots of light (indirect) was needed - and I am finding that not true. Example: I took a small plant of a H. aff. anulata from the Greenhouse to DHs office so that he could photograph the flowers with his new camera. (This H. aff. anulata has the same leaves as H. anulata but they are about 3X bigger...very pretty growth). Well,while the plant was in there(3-4 days), it grew a 2' vine reaching towards the window. OK..it is trying to find light...and this is how they grow in the forest, for the most part. Generally, they are understory plants, eeking out an existence on light and food available. Given that lower light, I think they grow faster (gotta get outta here)...their feet in the shade.
Conversely, growing plants in the brighter light, I see them growing towards the shade.... (I think they perceive the shade to be something they can then grab hold of to climb)...
At Liddle's Nursery, most of the hoyas are grown 80% shade...(shade cloth)...with the light moving over them, not constant, as the sun rises and sets. I did see H. pottsii growing wild in a park...and it was NOT in bright light.
No instructions here...just musings...thoughts about light. I am putting up 75% shade cloth on my greenhouse (can't get 80%) and creating even shadier areas under the benches to grow some of them that are deep understory types). Will let you know how it goes.
How much light?
Interesting....my Grandmother introduced them to me as a teenager as houseplants that can grow in low light.....
I have two hoyas, H. pubicalyx "Pink Silver", and one H. compacta Hindu Rope and both are doing great, so far, under a light for the winter. I sure hope they continue, I can't do much more for them until next May/June. Winter bleck! :-P