Carolina wild petunia (Ruellia caroliniensis) is a wild flowering petunia species native to the southeastern United States like South Carolina, Florida, Alabama, and Louisiana. It is planted ornamentally for its attractive flowers.
I. Appearance and Characteristics
Ruellia caroliniensis, the Carolina wild petunia, is a wild petunia with blue or violet flowers that appear in the spring, summer, and autumn. This species is native to the southeastern United States.
Ruellia caroliniensis (Carolina Wild Petunia) is an unbranched, spreading perennial boasting a profusion of trumpet-shaped, petunia-like, light purple flowers borne in axillary clusters of 2-4. Blooming for weeks from early to late summer, the blossoms have a slender corolla tube and 5 petal-like lobes. Each blossom lasts a day or two, but new flowers form in succession. They provide nectar for bees and butterflies.
Carolina Wild Petunia serves as a host plant for Buckeye butterfly caterpillars. The blossoms give way to seeds borne on hooked projections. The opposite leaves, 2-4 in. long (5-10 cm), are rich green, oval and medium in texture. A strong grower, Carolina Wild Petunia can spread, as it readily reseeds itself. Great as a flowering ground cover, for mass plantings, hanging baskets or cascading down a wall.
II. How to Grow and Care
Sunlight
Carolina wild petunia prefers partial shade to full sun and differs in appearance depending on the light it gets. Full sun results in purple stems, while shading produces green stems. In areas with the harsh sun during summers, it may do better in some shade. Bright, filtered sunlight is best if the plant is grown under glass.
Temperature
Carolina wild petunia favors warm, humid environments, as it originates from South and Central America as well as southern parts of North America. The coldest it can cope with is -9 ℃ for short periods. At the lower temperatures of the preferred range, it may grow slowly and produce fewer flowers. The same may be true at higher temperatures.
It prefers humid environments and consistently moist soil but can tolerate short periods of drought. Carolina wild petunia likes being near sources of water such as riverbanks or the perimeter of boggy areas. care should be taken when planting near these areas, as it can become invasive.
Watering
Carolina wild petunia likes humidity. If the humidity is high, it’s more able to tolerate dry periods. Most wild petunias prefer to be regularly watered to ensure they are kept medium to wet. Regular watering is particularly important during periods of active growth and in very hot, dry weather, water daily unless the soil is becoming boggy and waterlogged. Ruellia malacosperma, one species that is able to cope with being wet or dry, is an exception. Since this plant is fairly drought tolerant it is possible not to need to add water when it is kept outdoors.
plants may also be ready for watering if the soil beneath the surface is dry to the touch or the plant appears to be wilting. If the plant appears to be wilting, apply plenty of water. In more moderate weather, water weekly unless the soil appears very damp to wet.
Don’t water these plants in the afternoon, as the hot sun can cause more water to evaporate and even harm the leaves. If Carolina wild petunia is kept under the cover, water daily during the growing season and once a week during the winter. The pH of the water should be in the same range as for soil: 5.5-7.8, which means that most water will be satisfactory for this plant.
Soil
Carolina wild petunia can tolerate many different soil conditions. The preferred pH of the soil is 5.5-7.8. Soils that are fertile and organic and wet or boggy are favored. It is also able to grow well in average soil that has good drainage, providing it is kept consistently moist. Once established, it is resistant to short periods of drought. If grown in pot soil, it should have reasonable drainage, as diseases can occur if its roots are too wet for long periods.
Fertilizing
Carolina wild petunia can manage quite well without fertilizer. Apply a 10-10-10 mix in spring to feed the plant during its active growth period (10-10-10 means equal parts nitrogen, phosphorus and potassium: a general all-purpose fertilizer). Mix fertilizer with water. Indoor plants can be given a half dose of all-purpose fertilizer every 2-3 weeks; this is good for their leaf color. However, if too much fertilizer is applied, there will be fewer flowers.
Planting Instructions
Carolina wild petunia is readily available in pots or as seed, which can be sown outdoors in spring. Spring is also the best time to plant carolina wild petunia in the ground. It is not particularly fussy regarding soil type and copes with either good compost or native soil. When planting in the ground, chose a site with shade to partial shade.
Topsoil or peat moss can be added to the hole beneath the plant to improve soil structure and water availability to the roots. Water well after planting.
Carolina wild petunia attracts butterflies and hummingbirds. It’s best to plant in the ground, as rapid growth can cause it to outgrow containers quickly. That said, containers are useful planting options to restrict the spread of this plant.
Another method to reduce spread is to plant it behind solid edging, or have a regular maintenance routine to pull up every unwanted plant. Planting near wetlands is not recommended, as it is likely to colonize the area very rapidly. Although sterility stops spread by seed, it remains aggressive in its spread of roots.
Pruning
Carolina wild petunia does not require much pruning. Remove dead leaves and flowers after flowering for aesthetic purposes, and to stop it going to seed, which may result in spreading. Pinch young shoots to encourage branching and more flowers. Remove and dispose of the debris to avoid attracting unwanted bugs or animals. Damaged or unwanted branches can be pruned back to ground level in late winter or early spring.
Propagation
Carolina wild petunia can be propagated by division, sowing, or cutting. Dividing is the easiest method. Carolina wild petunia grows from rhizomes beneath the soil; these can be dug up and a portion split off and moved. Seed from fertile varieties can be saved and planted in spring in moist conditions and temperatures between 19 to 24 ℃. plant 1 or 2 seeds per plant wanted, spaced 30 cm apart. Softwood cuttings can be taken in spring or early summer. Cut cuttings of 5 to 8 cm length with 2-3 nodes. Put them in moist sand covered in polyethylene film. Keep moist but not wet to ensure the cuttings do not rot.
Transplanting
Carolina wild petunia ideally transplants in late spring to early summer as this provides optimal growing conditions. Choose a sunny to partially shady location for healthier blooms. When necessary, remember to water regularly after transplant to aid in the establishment stage.
