Because the considerable difficulty in cultivating this Hoya, I cannot give it an enthusiastic thumbs up. However if you are looking for a capstone challenge with your Hoya growing, then you will have to look far and wide to find a better candidate. Here are the conditions under which I believe Hoya undulata would grow best. Warm and humid, temps above 75 degrees F day and night, don’t give too much light as most LEDs stress the leaves and they turn red as a result. Water when almost totally dry; cross your fingers and hope for the best!