Tip of the Week — 3/30/09

Posted in Gardening Tips on March 30 2009, by Sonia Uyterhoeven

Pruning Roses

Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.

Common sense and experience tell us that a stitch in time saves nine. The same principle applies to pruning: A knick in time saves nine. This being the case, when is the best time to prune your roses? Traditionally, we go out and prune the roses when the forsythia starts to bloom. The reality is that you can go out anytime during late winter and early spring to cut back your repeat-blooming roses.

With springtime pruning, you are trying to conserve the plant’s energy. Watch your roses (or for that matter your Buddleja, Caryopteris, Hydrangea paniculata and whatever else you are planning to hack back), and wait until the buds begin to swell. This signals the initiation of growth and that it is a good time to jump in with the pruner’s saw. Do not wait until new branches begin to emerge, otherwise you will just end up cutting off new growth that has expended valuable energy—and it will go wasted.

Before you begin, remember these important rules:

1. Always cut out dead, damaged, and diseased wood first.
2. Remove any crossing or congested branches to enhance circulation
3. Then work from there.

Modern hybrids are fairly forgiving; you can cut many all the way to the ground and they will sprout again. In general, the harder the pruning cut the more vigorous the new growth. We cut most of our hybrid teas back to 8–12 inches (depending on the rose and the winter damage). Larger shrub roses are generally cut back by one-third.

We prune the roses back to an outward facing bud. This bud generally indicates where the new growth will come from. In roses it is important to create a nice open framework, so that you want the branches to be growing in an outward, vase-like fashion. Make the cut about one-quarter inch above the bud. If you cut too close to the bud, you may end up damaging the bud. We often cut the cane at a 45-degree angle facing away from the bud so that it will encourage rainwater to run off away from the new growth.

Remember that these rules only apply to repeat-blooming roses. Old-fashion roses that flower once per season are pruned immediately following flowering. These roses flower on old wood. If you prune them early in the season, you will be removing the flowers for the season. Old-fashioned roses have congested canes removed after flowering, and they are shaped and often cut back by one-third.

Don’t be afraid to prune your roses; they are fairly forgiving. Experiment to see what works best in your garden, and enjoy the learning process.