China roses are the oldest of the old roses. They are ancient hybrids raised, selected, and grown in China for many centuries. Examples are 'Old Blush' and 'Slater's Crimson', which can be traced back at least 1,000 years. They are the result of hybridization between Rosa gigantea, Rosa chinensis and, probably, Rosa multiflora.
The development of rose breeding started with the import into Europe of a handful of Chinese garden roses some 200 years ago. These roses were crossed with European cultivars to produce the great variety that emerged in the 19th century. The unsung heroes of rose breeding are the gardeners of ancient China who made it all possible.
The most important cultivars for the history of roses were called 'Hume's Blush Tea-scented China' and 'Parks' Yellow Tea-scented China'; both were introduced to Europe from southern China early in the 19th century. They get their name from their characteristic scent of China tea leaves, which is also found in many China roses. They tend to be very tender (only a few are hardy in Zone 7), but are tolerant of drought.
They do, however, have a convenient and practical logic which it is worth trying to understand. One of the most useful divisions, though rather arbitrary, is between old roses and new, or modern, ones. Old roses are those introduced before 1867, or 1900, or 1945, according to an individual's point of view.
Cross-breeding between them, and sometimes with the China roses and European garden roses, led to the development of thousands of hybrids. Examples are 'Anna Oliver', 'Catherine Mermet', and `General Schablikine'.
They vary enormously between the classes and it is worth studying the characteristics of each class, so that you know what to expect of them. The ancestors of our garden roses are the wild roses from which all our cultivated varieties are descended.
They originated in England, and were named after a Duchess of Portland. `Portland Rose' is low and spreading, like a feeble Gallica, but later hybrids tend to be upright and stocky, with very short nodes which give them a dense, leafy look. When the F.uropean roses were crossed with the Chinas and the Teas, the first recognizably modern roses began to emerge, though the Bourbons and the Hybrid Perpetuals are generally categorized as "old" rather than "new".
The Bourbon roses get their name from the dc Bourbon (now Reunion) where the original 'Bourbon Rose' is said to have occurred as a spontaneous hybrid between 'Old Blush' and 'Quatre Saisons'. They are repeat-flowering roses that descend either from the original or from similar crosses between China roses and repeat-flowering Damasks. They are 2-3m (6-1 Oft)tall, with an open habit, glossy leaves, and large, beautiful, sweet-scented flowers.