Periwinkles (Vinca minor) are evergreen perennials that produce bright blue flowers. ... Periwinkles are often grown as transplants, but they can be started from seed at least 10 to 12 weeks before the last frost with the proper care. They grow in U.S. Department of Agriculture plant hardiness zones 4 through 9.
Although this plant isn't frost-hardy, you can grow it as a perennial if you live in USDA plant hardiness zones 9 and above. Collecting vinca seeds from mature plants isn't difficult, but growing annual vinca from seed is a little trickier.
Annual vinca is a tropical/subtropical plant. In hot areas, they grow as a perennial. In warm areas they grow as a self seeding annual.
Vinca is grown as an annual. It will often return in following summers from self-sown seed.. . . . .364011236304!]0000000000000009783314144820!]
