When and how to divide periwinkle (vinica)

Divide them up now. Replant where you like for good ground cover.

They are so vigorous you can divide when ever almost. Once established an annual go over with the shears will further encourage flowering.

my vinca are very healthy and i like them. When winter comes, and they die, will they grow back in the spring ? They are in hanging pots. What can i do to get them back in the spring ?