Hibiscus (Hibiscus species, Zones 4 to 10) Bold, beautiful and impressive, this perennial grows up to 15 feet tall. Its huge blooms are 4 to 12 inches wide and last from early summer to the first frost. Keep this stunner in full sun and in rich, moist soil. Why we love it: Look for tropical species of these plants to add to your favorite container display. One plant alone will add a gorgeous touch of the tropics.