Climbing roses are often grafted hybrid roses with one type of rose with desirable characteristics grafted onto a rootstock of another type. Occasionally, the rootstock produces growth that attempts to bypass the grafted upper portion of the rose plant. The new rapidly growing canes arising from the rootstock are called suckers. The sucker canes are usually bright green with a leaf shape and colour that is different from the top of the plant and may also have few thorns. If allowed to remain on the plant, suckers will drain the energy from the top growth, eventually weakening or killing it.
Identify the suckers on the climbing rose plants. They will look different than the rest of the plant, be rapidly growing and attached to the area just below the graft or the underground root system. The graft is the swollen offset area just above the root system of the plant. It may be located above or slightly below the soil line.
Wear a pair of garden gloves so the rose thorns cannot damage your hands during the removal process.
Remove the soil from the base of the sucker so you can clearly see where it is attached to the root system of the plant. You will be able to see which way the sucker can be pulled or stripped away, from the root section. It should be pulled so that it forms a "heel" when pulled away from the root system. If the sucker is pulled in the direction where it has a lot of resistance, you may pull up the root system or the entire plant. Cutting the sucker away from the plant, rather than stripping it from the root system, will allow the site to heal.
Grab the sucker with both hands and yank it off the root system with a fast jerk. It should snap right off if you are pulling it in the right direction.
Cover the area where the sucker was removed with soil. Add a 2- to 3-inch layer of mulch over the soil around the climbing rose plant to help prevent new suckers from forming.