For you OGREs out there, Paul Zimmerman, master rose grower, has written a fine article describing exactly what an Old Garden Rose (OGR) is.
What is an Old Garden Rose? To history it is a rose being of a class in existence before the year 1867. Why 1867? Simple. This is the year a rose named “La France” was introduced. La France is considered to the be the first Hybrid Tea. It is the offspring of the Hybrid Perpetual “Madame Victor Verdier” with the Tea rose “Madame Bravy”. The hybridizer was Guillot and what marked La France as being different from other roses was the high centered blossom we associate with Hybrid Teas of today. The name Hybrid Tea in fact comes from a wedding of the classes of the parents of La France. A Hybrid Perpetual and a Tea rose.
Centifolia – Gros Choux de Hollande
Notice I use the words “class of roses” in existence before 1867. This means that even though say a particular Bourbon (a class of Old Garden Rose) was introduced after 1867 it’s still an Old Garden Rose. In fact it’s possible that an Old Garden Rose could be hybridized and introduced to the growing public today.
Here’s the rest: What Is An Old Garden Rose? <– Unfortunately, this link appears to be dead (as are all links to Paul Zimmerman’s old site) and a diligent search of the web failed to uncover a new location for this article. The article was quite good, so we will keep looking, and we will update the link if it reappears.