Hi Barmy! I bought Souvenir du DJ last year and I have to report that although it is a really stunning rose, and useful for a semi-shaded spot, it is also a devil for mildew. Its still growing for me, but slowly, and now that I've sprayed it, I'm hopeful for some blooms. I started it off in a large pot, but soon realised it would need to go in the ground, so moved it there last autumn. Good luck! Sorry I can't advise about the other one, but I know someone will. :D

As far as I can tell, Rosa Banksia should be pruned by having spent wood removed - if you want to renovate or reduce in size, best done immediately after flowering is finished.
As for Souvenir ... its listed as having 'average disease resistance'. Agree with Karen above reagrding a slightly shady spot - the flowers hold their colour better with less glaring sun. Not that there's much of that about in the UK this year...
I wondered what on earth you were referring to, Barmyphil, with your reference to one of my blogs - and then I remembered. It was the one about Guest Questions, where I said I thought our responses to those were often ruder than the questions themselves, isn't it. No worries mate - issue of Guest questions has long since faded - we don't have guest questions any more, lol. So don't be nervous, ask away, you're a member anyway!

I've been growing 'Souvenir Du Docteur Jamain' for several years with no problems except for a little blackspot on the leaves. It's growing against a west-facing fence, and planted in heavy clay and gets a general feed in early spring each year.

Thank you to karensusan6, Andrewr and Bamboo - your replies are much appreciated.

Yep, Bamboo is right. We grow a lot of Lady Banks' rose here, and, like all once blooming roses, it's best pruned right after blooming. We usually also prune them several more times through the summer, since they have ambitions of world domination, here, but stop in September to allow flower buds to develop. In the UK, stopping earlier is probably indicated.

Thank you Tugbrethil for your greatly apreciated pointers on rosa banksia. Im just going to read your profile, see ya.

You're welcome!