I received Hoya hamiltoniorum in a three-way transaction in September of 2019 meaning that Jimmy Meyers of North Carolina, and I split a 12 plant Thai order from Surisa Somadee. September is a very bad month to order from Thailand, and the plants came in pretty bad condition. It was in such bad condition that I had little hope that it would make it so I asked Jimmy not to send it, and see if he could make it live. He somehow managed to pull it off and sent me the plant in the summer of 2020.
Quite frankly this Hoya has not been a good grower for me at all, and I have yet to figure it out. It seems very susceptible to root rot, and I have had to start it over a number of times. It roots easily and puts out peduncles at every leaf node, but getting them to bud up is difficult under my conditions. I have 2 plants now after starting this Hoya over so many times. I was quite shocked that after so much time, my weakest plant put forth a peduncle that actually began to bud up in the spring of 2022. It was not strong and only manage to hold on to one bud. I was able to get my sad single bud to hold on long enough to open its flower, and I made the most of it by taking many photos.
Hoya hamiltoniorum is only known to exist in the central and southern Crocker Range in Sabah, Borneo between 600-1,200 meters and is named for John and Gina Hamilton, residents of Sabah, and avid growers of Borneo Hoya species. If I can ever figure out how to grow this Hoya, I would love to bring it back to this site. It has a unique flower, and some day I would love to flower a peduncle full of blooms. At this point I am happy to at least say that I was able to flower it. This Hoya is not a plant for beginners, and gets my recommendation for serious collectors only.