Drought tolerant. Heartleaf hibiscus grows well in a large container or in the ground. Trim off spent flowers to encourage blooming throughout the year, even in hottest weather. Mulch well to help it over winter in cooler regions. This plant grows in most soils and needs good drainage. – Do not over water!. Heartleaf Hibiscus is not cold hardy below 20 degrees. Propagation: Seeds.