The Rose of Sharon or Hibiscus syriacus, depending upon variety is hardy from zone 5a to zone 9 and I am a zone 3 or 4 gardener.
Soil ph ranges
From 5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
The Rose of Sharon is referred to in the Bible in King Solomon’s Song of Songs
I am the rose of Sharon,
and the lily of the valleys.
As the lily among thorns,
so is my love among the daughters.
As the apple tree among the trees of the wood,
so is my beloved among the sons.
The flower's symbolic significance stems from the Korean word mugung, meaning immortality.
If leaf spots are seen, pick off and destroy the infected leaves.If bacterial leaf spot causes problems, pick off and destroy infected leaves. Canker can kill branches or entire plants. Bright,reddish-orange fruiting bodies may appear on the bark.Prune out infected branches.
Flowers may be infected with a blight caused by a fungus.Bud drop can be caused by too much or too little fertilization. One potential problem that may affect the Rose of Sharon is during its first summer, if you live in a hot climate or have a particularly hot summer, the first year that you plant it, it is possible that the heat will kill the plant if it does not get enough water.
When most plants are first planted they usually need closer attention than they do when they have become established and this is especially so in extreme weather, excess heat or rain, for example.
The plant requires ample moisture and some protection from midday to afternoon sun if it is to reach its peak. The Rose of Sharon is a shrub that will keep its upright form as it grows. This means you will not need to do much pruning.
Best pruning times are late winter or early spring; this way you will minimize the loss of the emerging flower buds on the new growth.
Heavy spring pruning cutting back to nor more than 3 buds will produce fewer but larger flowers.