These are selected because of their ability to produce vigorous root systems. The place where the cultivar and rootstock are joined becomes distinctively swollen. All canes of the cultivar come from the bud union. From a gardener's point of view, this produces a rose that tends to have a better root system. From a nurseryman's point of view, budding results in plants that reach the market quicker.
Less time is spent in the production fields.
There are several pitfalls to be aware of with budded roses. Rootstocks of budded roses often send up suckers that produce leaves and flowers that are totally different from the budded cultivar. Suckers are also a common result when budded roses are killed to the ground during severe winters. That is why some roses mysteriously change identities between seasons, producing long, thin canes with different leaves and different flowers. Other problems that can occur are graft incompatibility, resulting in reduced vigor and death, as well as the transmission of rose mosaic, a virus infection that reduces the rose's performance.