Thanks for posting this, i was just getting ready to do the same post. I've two albas, mme legras de st. germain and konigin von danemark, they're both at least 6 years old, both totally different bushs for me. kvd grew up to be tall and very bushy,(7x7) nevered pruned it yet, and mlsg is just as you described long arching canes, no branching at all, i have it tied up to a small trellise right now, but would prefer it to grow more as a shrub. i was going to cut it back by a third after it is done its bloom cycle, any tips would be greatly appreciated here as well...mark

I don't grow Mme. Legras de St. Germain but my solution for Mme. Hardy was to stretch her horizontally across a tripod shared with Chapeau de Napoleon. The horizontal line increases blooms along the canes and the tripod provides structure needed for lax canes.

Sue

I prune my once-blooming roses when they are dormant in winter. Contrary to popular belief, you will not lose the summer blooms by pruning at this time. I prefer when they are dormant because they are less prone to shock if you need to prune them harder than 1/3 or remove old canes. Roses need some leaves in summer to feed so hard pruning can hurt them at that time, and then if you have a summer drought that can kill them if they are recovering from a pruning unless you are constantly watering (and I prefer to let my once-bloomers go dormant and be low-maintenance in the summer).

Anyway, prune them at the right time when they are dormant and you can develop more of a branching structure by pruning them low the first year, then a foot higher the next of the branches, and then a bit higher, and then get rid of the oldest canes and start over...encourage a vase-shaped branching structure that you need to build up over several seasons which constantly will get refreshed as you remove the oldest canes.

Here is thread that might be helpful:
http://forums2.gardenweb.com/forums/load/rosesant/msg0919121813540.html

To get those leggy ones to be fuller you can do some 'training pegging' Pull the long canes down and peg them in the early spring-they will break buds along the canes then let them go again. I do this with Chloris which wants to be long and lax and bare at the bottom. It also gives me something to prune down to when I shorten. I let some of my Rugosas go to long without pruning and am doing the same thing with them.

patricia

I do the same as Lori, prune them the way I want in December/January when they are dormat. Works well for my climate (6B).
Olga

what patriciae said. I peg most of my roses in late winter or early spring to get the laterals growing then unpeg them over the summer as the thought occurs to me (or I need to use the pegs on other canes). You can peg again when the roses put on another growth flush in summer.