Has anyone grown the Cora or Cora Cascade series of vinca from seed? I�m thinking of doing it this coming year and would like to get an idea of the difficulty or any tips on how to do this.

In the spring of this year I bought some 4" pots of Cora Cascade in white and they have done very well in the full sun of my garden in Raleigh, NC.

I like the colors in the Cora Mix Vinca Flower seeds at Park Seed, but am also interested in the Cascade series.