Answer: There are two main possibilities for why your Rose of Sharon (Hibiscus syriacus) hasn't bloomed. This shrub blooms during summer on the current year's growth. This means that any trimming or shaping or pruning must be done in the very early spring. Many gardeners trim this shrub back very early each spring to promote blooming. In other words, if you trim it during the growing season you will remove the flowering wood.
Another possibility is poor growing conditions. This shrub is not too particular about soil as long as it is not excessively wet or dry, but it does need sun. Full sun all day is ideal since this is a plant that prefers hot weather, but a half day of full sun will also do. If the shrub is in a shady spot, it may bloom sparsely or perhaps even not at all.
I hope this helps you figure out why your shrub hasn't bloomed!
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