If it were to do over again, I would grow this species in a hanging basket. It does not twine, is a rampant grower once it gets going, and is difficult to keep up with tying to a trellis. This plant would also do best where it could actually get less light. My grow tents are over lit and many species get sun stressed and Hoya tsangii is one of them. The leaves get red and blotchy from too much light. I believe they look best when kept nice and green. Below my plant in its entirety:
Here is a comparison photo of these two Acanthostemma Section Hoyas:
Unlike most Acanthostemma Section Hoya, this species flowers did not have a strong scent of caramel. The scent was light, fresh and almost imperceptible. The flowers are very small as can be seen in this photo comparing the entire umbel with a quarter for perspective.
Hoya tsangii is one of those rare Hoyas that open its flowers in the day light, and do not open them in the dark. The flowers opened over the course of three days; first two flowers, then six flowers and finally nine flowers.
This plant was not a quick bloomer that would flower withing a few months from cutting. I was beginning to wonder if it was ever going to bloom, but right around the two year mark it put out its first peduncle and began to bud up. Below the buds of Hoya tsangii:
Hoya tsangii was given to me as a small cutting by my friend Wil in the summer of 2022. It rooted quickly in coconut husk chips, but for some time was a very slow grower. Eventually it started growing much quicker and went through a couple of up-pottings eventually ending up in a five inch clear orchid pot.
Hoya tsangii was first collected by Daniel Edward Elmer in August of 1912. He found it in the Philippines, Mindanao Island, Agusan del Norte, Cabadbaran (Mt Urdaneta). Unfortunately, he labeled it incorrectly as Hoya angustifolia an invalid name. This was only the beginning of the confusion with the taxonomy of this species. At one time or another it has been called Hoya burtoniae, Hoya odetteae, and Hoya sp. aff. burtoniae. These are all incorrect; this plant belonging to the Acanthostemma Section of Hoya, with the little yellow flowers, is now definitively known Hoya tsangii. A big shout out to Mary Caroll for providing me with much of this research!
Hoya microstemma (NS11-145) is a easy growing small Hoya that gets my highest recommendation. I believe with careful tending, this could be a spectacular small specimen plant after a couple of years. The flowers last for about 3 days, don’t drip nectar – a huge plus, the leaves get beautiful red tinging in high light, and there is nothing bad to say about this fine little plant. Pick one up today!
I have only been growing this plant now for around 8 months or so, but I believe this plant might be best appreciated when grown in a small hanging basket with several cuttings. It grows slowly and does not twine so I would think a hanging basket would be best, and after my plant gets large enough to take a few cuttings, that is probably the direction I will head with it. Below is what my plant looks like after eight months on a trellis:
The blooms are pretty small as can be seen in the photos below:
