Periwinkle prefers full sun and takes a long time to flower when started from seed. The brittle stems break easily. The plant tolerates heat and drought and can be relied on to flower in the hottest weather. Grow Periwinkle in sun or shade.
Propagation is by seed or cuttings.
Softwood cuttings can be taken and rooted during summer. The seed germinates in two to three weeks at a temperature of 70 to 75 degrees. Keep the flat in the dark until the seed germinates and don't over-water. Thompson and Morgan 1997. This information is for educational purposes only.