Spring Pruning for Roses
(This article was first published in The Gateway Gardener April 2009 issue.)
By Diane Brueckman
April 15th will soon be here and you’ll be uncovering your roses. Pruning is an essential part of having good-looking, productive plants. Removing dead and diseased wood not only shapes up your plant, but gives you more and bigger blooms. Pruning is a great way to revitalize a tired old shrub, as well as those all too healthy “Knock Out” roses that are taking up more space than you would like. One word of caution: if your rose only blooms once, spring is not the time to prune it. The Species and Old Garden Roses should be pruned after they bloom.
If your plants have only been in a year, keep the pruning to a minimum. Removing the dead wood is all that is necessary. Climbers should be three years old before they are pruned. This gives the plants time to establish good root systems before they are cut back.
Start by removing all dead wood. Then go for the diseased wood. Unhealthy canes will be
brittle or soft and squishy and either black or dark brown. These canes often harbor disease spores and overwintering insects, their eggs or larvae. Look for irregular blotches that can be cankers (a fungal disease) and should be removed down to good clean wood. Healthy wood will be green, red, purple, chartreuse or a mixture, and when cut will have a clean white pith in the center.
Now look at shaping your plants. Remove canes that are thinner than a pencil or crossing through the center of the plant. I hate it when I find two good canes rubbing against each other. A decision must be made to trim one out altogether or at least before the point of contact. The small spindly growth at the base and center of the plants will impede air circulation and sunlight thus encouraging disease and insects. Trim the healthy canes back for a symmetrical look. Always cut to an outside facing bud at a 45 degree angle about 1/4 inch above the bud. Of course, your plant may decide to grow from a bud further down the cane or pointing in toward the center of the plant. A word of caution; do not cut the graft union. A bad cane can be cut to the graft union but go no further.
Hybrid teas and floribundas can be cut as low as 6 to 12 inches, but if the canes are solid and healthy leave them as tall as you want. Leave all the healthy canes.
Trim your miniature roses as you would a tiny shrub. Don’t worry about individual cuts. You’ll want to leave shrubby roses taller but still thin out the centers. Don’t cut off more than 1/3 of the total mass.
I have seen too many shrub roses that have not been pruned and after a couple of years the centers are a tangled mass of leafless dead canes. At that point, the job of cleaning them up is monumental. To paraphrase, a snip in time saves nine.
I usually prune my climbers from late February or later. Again you are removing dead or diseased wood. The big difference with climbers is the canes that need to be removed are cut all the way down to the bud union. Ideally you will have at least 4 to 6 good young canes to keep and train onto your support. The lateral shoots (those coming off the main canes) are then trimmed back to 4 to 6 leaf buds. These lateral shoots are going to give the plant its blooms. Remember to put some stress on the main canes by bending them along their support, this will encourage more lateral shoots.
Diane Brueckman is a retired rosarian with Missouri Botanical Garden, and currently owns Rosey Acres in Baldwin, Illinois. You can reach her at (618) 785-3011.