Answer: Rose of sharon or Hibiscus syriacus is considered to be a fairly sturdy and resiliant plant. The old fashioned types (usually pink, yes!) are known to self seed with abandon. Some of the newer hybrids are considered to be sterile and will not seed about, others of the newer types simply seed about far less than the old muddy pink ones did. In my experience some of the newer types have lovely flowers (in new colors such as white and near bue) but are also slightly less vigorous in the garden than the old fashioned ones are. These newer types may take longer to become established and may require better care and better siting in order to perform well. They need full sun, adequate water and soil that is at least average but preferably rich, evenly moist and yet well drained. In other words, they are not as vigorous as the old fashioned types are and require more care especially when newly planted.
In general all of these shrubs are slow to wake up in the spring and leaf out very late. They may also experience some winterkill to the branches. They should be pruned back in late winter to remove winterkill and to encourage branching. Older, overgrown shrubs can also be pruned to the ground to rejuvenate them. They will appreciate some compost, aged manure and/or complete fertilizer in early spring and again in June. Apart from that, and a routine mulch, they should not need much care once they are established. During the establishment phase, however, they need to be watered as would any other new shrub. The soil should be kept evenly moist but not soggy wet. The pst few summers have been excessively hot and dry, so this may account for the problems you have experienced.
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