'Graham Thomas' has certainly been a productive parent. I notice MR is being grown in two zone 5a gardens and sold by Rosarium in Spokane, WA. I wonder if this might be a good alternative for those of us who can't grow GT?
Star roses and plants is listing the hardness zone of MR as USDA 5-9 so I think it’s worth a try. But for me it doesn’t look like Graham Thomas so much, the plant is more like a very big traditional hybrid tea rose, even the flower color is a bit different from that of GT.
I live in upstate NY, along the Mohawk River, so in a frost pocket. A number of borderline tender roses have not survived the winter for me, despite being covered. I tried 'Sunflare' twice, alas, as it is a favorite of mine.
That’s discouraging. I love mine. Have you tried growing it own root? In my own experiences with zone pushing, an own-root rose may be killed to the ground, but often still come back in the spring. That’s not usually the case grafted.
I have several own root roses which do come back, as you say, but they don't grow very much during the rainy summers. I am keeping them because they are extremely rare, and I am still trying to figure out how to propagate roses in my climate without having to buy an expensive misting system.
Have you tried Mike Shoup's ziplock bag technique? This is a variant of it (replace dot with .) heritagerosesdotorgdotau/articles/rose-propagation-ziplock-bag-technique/ Mike recommends about equal amounts of potting soil and aerator, eg perlite - I don't use any aerator but our potting mix here must be very different from what he uses. It needs about 6 weeks of warm weather - might be borderline late for you this season.
this rose, now in october, is between 6-7' feet tall in its bed at the lyndale park rose garden in minneapolis, mn in z4/5. looks to be healthy, with a very upright growth pattern. i would say it has good cold hardiness judging from the size and vigor of these bushes.
to me as well, it looks more like a hybrid tea than a graham thomas, which i have in my garden.
