Pruning Roses Watch for Rootstock Growth That Overpowers the Plant

Q. I haven't pruned my roses back yet because there are still blooms. Should I wait awhile?

How far back should I trim; 1/3 or 1/2?  I have two favorite bushes that are 4-5 feet tall with very thick canes. How severely should these be cut back?

Strong growth from the base
can mean the rootstock has
taken over

A. You could wait a bit on the roses if you want. Wait until total leaf drop and then prune. If they do not drop their leaves, then pull the leaves off sometime in late December or very early January and do your pruning.

            Depending on how warm the microclimate is in your yard try to prune before you see any new growth early in 2012. This could be a bit tricky because in warm microclimates they might hold their blooms and leaves or continue blooming well into December and even January. 

            I would not wait past the first or possibly second week of January to get it done. If there are still flowers and leaves, harvest and enjoy them inside. Most garden roses have some scent to them, unlike greenhouse roses. If the leaves have not dropped, pull or cut them off before pruning.

            Make sure this strong growth is not coming from the rootstock. This is frequently the case on homeowner’s roses. The top of the plant dies back and they see this very vigorous growth coming from the base of the plant and oftentimes growing straight up. The dead growth is removed and the strong growth is permitted to remain. This is growth from the rootstock.

            You should still have a bud union (look for a “dogleg”) on the stem coming from the ground. If this bud union was lost (the rootstock grew and replaced or overpowered the top of the plant) then replace the plant.

Nevada rose

            The homeowner sees this strong growth and thinks “WOW, I am going to preserve this cane because it is doing so well!” The rose used for the rootstock will also produce flowers so there is even less incentive to cut it off. You can leave it on but it will have inferior blooms to hybridized roses and very vigorous growth harder to control.

            How far to cut back depends on the vigor of the plant, the type of rose and where you want to see the flowers produced. If you think the plant does not have the rootstock taking over then cut back about two feet below where you want your flowers produced. You may have to modify this if the canes are enormous.

            Select four to five major canes growing outward in different directions that you want to keep and remove the rest making clean, fresh cuts. Sharpen and sanitize your pruners before pruning. The local Rosarians usually have a rose pruning class in January so I will keep posted as soon as I hear of one.