Removing Suckers
Roses that have been produced by grafting may develop suckers; these are shoots that grow from the original rootstock, below the bud union. Not only will suckers spoil the look and shape of the plant, but they can also divert energy from the rootstock, away from the cultivar. If left untended, they may eventually completely overwhelm the plant and revert it back to the original rootstock variety.
Method
As suckers originate from below the bud union, they often grow from below soil level. To remove them, gently scrape back the soil to reveal the rootstock and then pull the sucker away, making sure that it detaches cleanly.
Avoid the temptation to cut suckers away at ground level; this will have the same effect as pruning and will encourage more vigorous growth, diverting even more energy away from the cultivar.