Thank you one and all-I truly appreciate your thoughtful comments.Seil, I'm in Italy, in the foot-hills of the Appennines, Tuscany. In theory the zone is estimated to be around 8, for what that's worth. Summers here are awful-very long, very hot, and very dry,and what's worse, my garden-a 20 minute drive from my home, without running water-faces south-west.
I've grown RdV before, and it gets to be quite big, but by no means is it a Hulk. It's very, very lax, and needs support, IME. Ideal on a tripod. I don't have much disease pressure at all.
I like to have the plants intermingle as much as possible,and this desire has caused me to plant roses too close to each other. What has me confused here is that I'd like to follow Arico's rule,but don't understand how to evaluate the "width" of a plant like RdV,since in my climate it just doesn't seem to want to be a self-supporting shrub-it wants to be a small climber. So I'd like to-if possible-plant something at it's feet, as Calsurf suggests, not just to hide legginess; what I'm envisioning is RdV grown together with some really dark purple. The dark purples that I have (also in pots, like RdV, and waiting to be planted out next autumn) are: Ebb Tide, Forever Royal, Purple Lodge, and Twilight Zone,so ideally I'd like to use one of these. Any further thoughts or comments, please?