Hoya sp. EPC 207 needs high humidity to grow well, or as a matter of fact to grow at all.  Don’t think that you will see any growth during the winter when the plant sits on your windowsill in your centrally heated home – simply won’t happen.  As well as this plant did for me in my indoor grow tents, it is growing much faster in natural light in my outdoor summer greenhouse.  With very warm temperatures, and high humidity, it will grow very rapidly and will twine around everything in sight.