I have 2 different varieties that I want to plant across the back wall of my back yard, Vanilla Ice and Velvet Queen. My questions are, 1) Should I alternate them (red, yellow) and just do a straight line? 2) Should I do them more in bunches? 3) Do they flower all the way up the stem, or only at the top?
Are you planting from seed? If so, read your seed packets to determine which is taller at flowering time. You could put the taller ones in the back next to the wall and alternate with the shorter ones in front. I'm not sure, but I think Vanilla Ice has more that 1 flower per stem.
As always, there are as many answers as there are gardeners. I'd bet that most of us do as I do, and learn by trial and error as much as anything.