The ultimate size depends on the parent plant. Climbing miniature roses, for example do not get very tall. Tree roses, or standards, are actually hybrid teas or floribundas grafted onto a 3-foot stem which has been grafted onto the understock. Sometimes miniature roses are also available as tree roses. All of these categories tend to bloom in cycles, beginning in early spring and ending in late autumn.
Roses are by no means low maintenance.
Hybrid teas, grandifloras and floribundas require annual pruning. Climbing roses require some degree of pruning and training to prevent a thicket of canes from developing. All do best with regular fertilizing during the entire blooming season. Irrigation must be frequent enough to prevent the roots from drying, but not so often that the roots rot in muddy soil. It is advisable to water roses in the morning so that they are not subjected to high humidity over night.