The types of petunias best suited to growing in South Carolina are the multifloras, millifloras and spreading petunias.

Grandifloras: Grandiflora petunias generally do not thrive in South Carolina because their large heavy blossoms are prone to damage and rot during hot, humid summers. Grandifloras have large flowers that are often frilled or ruffled along the edges. If you grow most grandiflora petunias, be aware that they will need extra care to look their best. The following cultivars are adapted to the South.

* ‘Storm’ series petunias are weather-tolerant and have high disease tolerance, uniformity and 3-to 4-inch blooms.
* ‘Ultra’ series petunias are compact and low-spreading with masses of 3-to 4-inch ruffled blooms.

Multifloras: Multiflora petunias are durable and prolific. Their flowers are not as large as the grandiflora types, but they are very free-flowering and vigorous. Multifloras produce masses of color through summer until frost. They are resistant to petal blight. There are single-and double-flowered multiflora petunias.

* ‘Carpet’ series petunias are available in many colors. They are compact, early blooming with 1½-to 2-inch blooms.
* ‘Primetime’ series stay compact and uniform, covered with 2¼-inch flowers.
* ‘Heavenly Lavender’ is an early, compact, double, deep lavender blue with 3-inch blooms on 12-to 14-inch plants.

Floribundas: Floribundas are intermediate between the grandiflora and the multiflora groups. They are free-flowering like the multiflora varieties and produce medium-sized blooms.

* ‘Celebrity’ series petunias are compact and rain-tolerant. The flowers reach 2½ to 3 inches across.
* ‘Madness’ series petunias have big, 3-inch flowers in many veined and solid colors. They are compact and bloom until frost. They bounce back well after rain.
* ‘Double Madness’ petunias are compact and floriferous with big, 3-inch flowers all through the summer. Like their single counterparts, ‘Double Madness’ petunias bounce back within hours of a rainstorm.

Millifloras: Milliflora petunias are much smaller than any other petunias on the market. The flowers are only 1 to 1½ inches wide, but what they lack in size they more than make up in number and duration. They rarely need to be pruned back in midsummer to rejuvenate.

* ‘Fantasy’ forms neat, compact mounds 10 inches high in the garden. They are excellent for containers and baskets.

Spreading Petunias: These are low-growing but spread as much as 3 to 4 feet. They form a beautiful, colorful groundcover because the flowers form along the entire length of each stem. They can be used in window boxes or hanging baskets.

* ‘Purple Wave’ produces large blooms of deep rose-purple. It is tolerant of summer heat, drought and rain damage. ‘Purple Wave’ remains under 4 inches tall.
* ‘Wave’ series petunias are available in several new colors in addition to the original purple. While the pink, rose and white ‘Waves’ are not quite as ground-hugging as the original, they are weather-tolerant and heavy-blooming.
* ‘Laura Bush’ is a reseeding old-fashioned petunia with violet flowers. It is disease-resistant and cold-and heat-tolerant, with a low-spreading growth habit.