Hardy hibiscus should be available in your area. Unfortunately we at the Q&A service don't have information regarding availability in various outlets across the country. You should ask your Home Depot Garden Center manager about future shipments and availability of this plant.
Regarding the carnations the symptoms point to a soil moisture problem, either too dry for a time or too soggy wet for too long. Water to wet the soil but then allow the roots to dry out just a little before watering again. They love sun but can't take the full summer sun, so a part sun and part shade spot should be nice.
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