A site about growing Hoyas in the Northeastern United States
Hoya griffithii Blooms June Through August in Southern China
While Hoya griffithii blooms June though August in its natural range, for me it only blooms in the late fall, or early winter. Here is a flower comparison photo showing the differences between H. Halconensis and H. griffithii.
Hoya halconesis on the left and Hoya griffithii on the Right.