I've grown a variety of roses year round in the greenhouse with very good success. What I find is that the roses get really thick canes, and much more substantial stems in the greenhouse than they do outdoors. It is fairly easy in the greenhouse to produce florist quality roses with minimal care. I don't use any pesticides, relying on beneficial insects which I introduced one time about 11 years ago. The beneficial insects keep bug pests under control all year, with the notable exception of about one week early each spring. During that week, I will get a massive aphid bloom. The roses will be covered with aphids, and dripping honeydew all over the ground. I have learned that this is a very temporary situation. The beneficials in the greenhouse attack the aphids, and, after that week bloom, the aphids are again under control, and the beneficial insects have had a very good set of meals. I find that I have no fungus problems in the greenhouse. One of the biggest issues I have is pruning; greenhouse roses get huge, and if not pruned, can be quite overpowering. It is not uncommon for them to be 9-11' tall inside, while they would be 4' outside. I prefer to grow a smaller number of very substantial (2" diameter) canes, rather than many smaller canes. The thick canes produces cut roses with stems that are substantial; thick stems mean extra nutrient storage for the flower when it is cut. Everyone has particular favorites when it comes to roses. I particularly like the behavior of some of the Austin roses, including Gertrude Jeckel because they grow large flowers, and perfume the house. Queen Elizabeth looks like another plant when grown inside: the roses last a long time, and have great substance. Perfume delight, while not as vigorous as some other varieties, does have a wonderful scent. Many of the standard tea roses do well, but I usually find there is an Austin rose I prefer over any other given tea.
Renais