Rosy Periwinkle Propagation

Location

• Rosy periwinkle plants prefer hot weather and high temperatures. The plants grow in USDA hardiness zones 9B through 11, meaning they are limited to use mainly along the extreme southern edges of the United States, such as the tip of Texas, the coastal regions of California and the southern half of Florida. Rosy periwinkle will tolerate partial shade and may benefit from a degree of protection from harsh midday sun.

Timing

• Plant rosy periwinkle any time of the year if you live in a suitable zone, but for a better start, delay planting during periods of high temperatures, or start plants several weeks before peak temperatures occur. Do not plant during cool spring weather.

Starting Seeds

• Fill a seed tray with soil and barely moisten it, scatter the seeds on the soil's surface, cover your seed tray with a black plastic trash bag, and heat the tray from below to provide a soil temperature of 77 degrees F, suggests the Colorado State University Extension. The plants grow from seeds to flowers over a period of six to eight weeks.

Transplants

• Space live plants 12 to 20 inches apart, and allow them to grow to fill in the areas between. The plants have a spread of 1 to 2 feet and a mounded habit. Transplant on a cloudy day, and mulch the plants to reduce water splashes that may aid in the spread of fungal diseases.

Water

• Rarely, if ever, water rosy periwinkle. The plants are drought tolerant and many of their disease problems are related to too much water. While the plants tolerate a wide range of soils, they require a well-drained soil and proper air flow among the plants.

Limitations

• Thanks to cross-breeding of rosy periwinkle with other species, a range of colors, habits and flower sizes are available, according to the Louisiana State University Ag Center. However, problems with disease were introduced along with expansions in periwinkle options. For example, while rosy periwinkle plants can grow as perennials, they are usually annual plants as a result of the prevalence of root rot. The ‘Carpet’ and ‘Little’ series will not exceed 12 inches in height due to issues with root diseases, according to the University of Florida IFAS Extension.