Prior to 2019 when I moved to a retirement community, I had a small hilltop farm and set about collecting fragrant disease-resistant roses for my gardens. Peter Kukielski's book "Roses Without Chemicals," mentioned in tantefrancine's post was my guide, and I visited numerous public rose gardens to see for myself. Out of the many Kordes cultivars I planted, 'Savannah', Beverly, and 'Wedding Bells' were my favorites.
Disease resistance is necessary but not sufficient for growing beautiful fragrant roses. A big discovery for me was the major impact of pests (e.g., aphids, thrips, rose slugs) on my roses, even though the air circulation in my breezy hilltop gardens was good. Pests seem to prefer fragrant roses, as I soon discovered in the second and third year of my rose gardening. My first year was pest-free and the roses were beautiful. But starting in year two and culminating in year three, even on roses that were highly resistant to blackspot and mildew, pests disfigured the rosebuds and made the edges of petals brown, especially those of white roses. Interplanting of Allium and other plants that supposedly deter pests around the roses had little to no effect. 'Savanna' fared better than other cultivars. The problem was at its worst during the first and second seasonal flushes. By October, the pests were mostly gone and the roses were generally beautiful.
In the retirement community where I now live, I have only one rose in my garden. I think it is Chrysler Imperial, which is very fragrant and dearly loved by the pests that live here. I found that the pests mutilated all the rosebuds and turned the edges of the petals black. Last summer I discovered that I could reduce the pest damage by spraying the developing buds with 2% Murphy's Oil Soap, with special attention to targeting the areas between the developing petals where the pests seemed to lurk. Since I have only one rosebush, this is a practical solution for me. Rose slugs were the problem at the time I discovered this solution, so I have not yet had the opportunity to determine whether it works earlier in the bloom season. Blue sticky traps set out near the rose bush did not work at all.
I wish you success with your fragrant rose garden project and hope that pests are not as much of a problem for you in Maine as they are for me in Pennsylvania.