Hoya obtusifolia came to me as a free cutting sent by a very nice collector in Florida. She said “if you can grow Hoya imperialis, you can grow Hoya obtusifolia.” Well, that turned out to be only partially true! The plant is endemic to S. Thailand, Peninsular Malaysia, Singapore, Sumatra, Java, and Borneo. It is a robust climber, and its name is derived from the shape of its leaves which have an obtuse apex.
I received a cutting of Hoya obtusifolia in the early summer of 2017, and it took a very long time to root. I have subsequently learned that this plant roots very quickly in water, but did not know it at the time. After rooting it, the Hoya grew quickly requiring several repottings over the course of a few months. My very first winter with Hoya obtusifolia it formed a peduncle, which excited me to no end. I thought that I was on my way to flowering this plant in record time being much quicker than Hoya imperialis – nothing could have been further from the truth! The excitement of my first peduncle quickly faded, as months went by with no budding, and the peduncle soon yellowed and fell off.
The plant was growing larger all the time, and with its very stiff vine, so similar to imperialis, it was very hard to keep in check. I moved it outside in the summer of 2018 where it formed many more peduncles, but refused to bud up. In the fall of 2018, I put the plant back into the basement grow tent under a powerful LED light. Over many months the peduncles would get barely visible buds that would quickly fall off before anything came of them. It was very frustrating. I finally asked the woman who gave me the plant how, and when it flowered for her. She told me that it would bud up in September and flower in October as day length was shortening. That statement was revelatory!
If Hoya obtusifolia flowered when the day length shortened, why couldn’t I achieve that same thing under lights? I moved the plant out of one grow tent with 15 hour days and moved in to another with 12 hours of light and 12 hours of dark. It immediately began to bud up, making me confident enough to tell my friend Julie Kennedy that I was going to flower the plant in a couple of weeks. I spoke much too soon! It was not two days after telling Julie that I was going to flower this stubborn plant that the buds began to yellow and fall off. Some of them were as large as a 1/4 inch in size. It was crazy, and I was beside myself! I was so angry that I told myself that I was going to put it outside in the summer of 2019 and give it one more chance before I threw the plant into the compost heap. It grew well that summer and just before I brought it inside for the year, it started to bud up again. My problem was I could not leave it outside like my friend did in Florida to get it to flower, as it would freeze long before it flowered. I had no choice but to put it back inside the grow tent.
I had literally hundreds of buds some getting quite large. Once again I was feeling confident, and once more I was to become very disappointed. The buds began to yellow once again! The only thing that saved me this time was that two buds out of hundreds made it to around a half inch in size, and eventually opened for me. I was so happy that I could check this one off my ‘have to flower list’, even though it was far from an impressive floral display. Hoya obtusifolia with only two flowers opened smelled lightly of melon, or cantaloupe to be more precise. It still galled me that I only got two flowers to open on this plant, but at least I got to experience the smell, touch, and photograph the flowers. Sadly after the flowers were spent, I had to get rid of this plant as it had grown too large for me to handle any longer. For some strange reason after all of the aggravation this Hoya caused me, I did save a nice cutting of it.
For those of us in the north, I cannot really recommend this plant unless you want a fast growing vine to go around a sun room. Even when used in this capacity, you would be better off with one of the much stronger and easier to flower imperialis clones. If however you live in Florida or the tropics, it could be just the ticket for you!