The grade of the rose is the size of the rose when it is harvested from the growing field. The grades reflect the number of canes a rose must have, the size of the canes, and where the measurements to size them are taken. Choosing a grade really depends on your budget and personal preference.Grafted Grade 1 roses are the top grade. They have three canes branched no higher than 3 inches above the bud graft and measure at least 5/16 inch in diameter. Grade 1 will be the most hardy plant because it has more canes. Grade 1 roses are the most expensive; prices decrease by grade accordingly.Grafted Grade 1.5 roses are one step down. A grade 1.5 rose has at least two strong canes and measures at least 5/16 inch in diameter.Grafted Grade 2 roses are the smallest grade. They have one 5/16-inch cane and at least one at 1/4 inch.Own Root Roses are graded using standards from a different grading category than grafted. They are graded as deciduous shrubs and may have canes that are smaller in diameter than their grafted rose cousins of the same Grade.