Hi Mari33 - welcome to the rose forum.
I live on Long Island zone 6B. In general, I would recommend the Kordes roses from 2002 to date. It is my understanding these roses were field tested for disease resistance. Steve mentioned South Africa. I have 2 SA - they do very well here also. Carol mentioned a book that I wrote an article about:
https://garden.org/ideas/view/...
The author offers suggestions as to which roses do well in particular climate regions.
Please feel free to contact me about any of the roses on MargieNY's plant list.
https://garden.org/lists/view/...
As far as performance and disease resistance is concerned the one hybrid tea that stands out above all the rest is: Electron.
My best grandiflora - South Africa do not hesitate to get this one.
Floribunda - honestly, all floribunda's I have in my garden do well. Betty Boop does get blackspot but it recovers very quickly and in my opinion worth keeping. I have a rose named Midnight Blue and for the 1st 3 yrs. had blackspot. However, by the 4 year, it had built up a resistance to b/s. The same thing may happen with Betty Boop - sometimes you just have to give them a chance to build up their immunity. It is my understanding it takes 3+ years for a rose to reach maturity.
Each summer, I map out my garden and document the number of hrs. of sun, shade, partial shade etc. in each garden bed between the hrs. of 7 a.m. and 5:30 p.m. Over the winter, I use this information in planning my rose garden for the following Spring. It aids me in deciding where a new rose will be planted or transplanted or shovel pruned.
I map out my garden using paper and pen. As a backup, I use a google Picaso program. One of their features allows one to create a picture collage. Example: 1) I take a photo of one of my garden beds
2) I site & add photos of the plants I want to add to my bed - the photos are scattered so you can move them around where ever you want 3) add text names of each plants 4) save it.
I found that I had more success growing hybrid teas by providing shade to this type of roses during the warmest time of the day.
1) early morning sun from 7-11 a.m. allows for dew or overnight rainfall to dissipate- be absorbed.
2) the partial shade from 11 a.m. - 2:23 p.m. allows for transpiration - cool down
3) the full sun from 2:30 to 5:30 p.m. combined with the morning sun offers a total of 7 hrs. of available sunlight.
Result: this garden bed seems to resists blackspot.
I don't know where you live in zone 6 but here on Long Island (hot & humid) it can be a big problem.
And lastly, I don't know if you are familiar with the symptoms of rrd - please take the time to look over the following link:
The thread ""The cat is out of the bag"" in
Scientists Seek Public Assistance in Tackling Rose Rosette Disease
