I received seeds form a red perennial rose bush from a friend. I started them indoors in January. The plants are about 12 inches tall. I had also started some of them last year, and they did well. . . bloomed the first year. I had planted them in two different locations in my yard. This year I would like to add one of the new plants in the same area as the one that I planted last year. How far apart should I plant them?