The first thing to know is what kind of rose you're dealing with. The classic rose, a single large bloom on a long stem, is a hybrid tea rose. It’s a hybrid between a tea rose, or tea-scented Chinese rose, which provides strong rootstock, and another selected for its flower size, color, petal count and aroma.
During the summer, pruning happens naturally every time you clip a flower and stem. Whether you decide to clip your roses early for display or leave them on until they fade, remove blooms to encourage more to come. Prune hard in late winter, while the rose is still dormant. Once canes begin to sprout new stems you’ve lost your window. You can still prune but expect less vigor from the rose that season.
Pruning prevents roses from squandering energy in random growth.
Yes, this is an entire step! Roses didn’t gain a reputation as finicky and sickly for nothing. Plant diseases like powdery mildew and black spot can be easily transferred between plants with dirty cutting tools. While it may not kill the rose, disease can weaken a plant and reduce its flower power. Wipe down your pruners, saws, loppers or other tools with isopropyl alcohol. Leather gloves offer the best protection from pesky thorns.
The ideal shape of a hybrid tea rose is a vase. Strong branches should grow out, not into the bush. Breezes are the natural enemy to plant disease and therefore an open, airy structure with lots of room for air movement and sunlight is the best for health of the plant as well as displaying showy blooms. If multiple roses are growing close together, it’s more important to increase air circulation and remove crisscrossing branches than it is to create a perfect vase silhouette.
Find any wood that is blackened and dead, cracking or has scaly bark. Locate a growth node, or bump, that faces outward. Canes will grow in the direction the bud faces. Choosing an outward facing bud ensures a better vase shape. Cut at a diagonal about one centimeter above the bud. If you cut at 90 degrees, you basically create a tiny bath that pools water and harbors disease. Anti-fungal powder can be applied at this point but it’s often better to simply let the plant heal itself.
Prune any branches that cross or rub against another. Next, you're going to take the whole bush down to about 10 or 12 inches high. It sounds drastic, I know, but roses grow like crazy in the summer so start them out with a stout base. Locate outward facing growth nodes around that height and cut a centimeter above, always at an angle. If you cut too close to the growth node, you risk damaging it. Too high and you’ve made yourself a "coat hanger." This, too, can die back and damage the node.
Locate any canes sprouting from beneath the graft joint. Hint: The leaves may be a different color or size from the main plant. These canes are suckers! They’re sprouting from the (less-desirable) rootstock and will rob your plant of energy. Here’s the rub: You can’t just cut off suckers. They’ll grow back! A sucker must be pulled off, so that all growth cells come off with the cane. Use gloved hands and a steady rocking motion to gently (or not-so-gently) remove the whole sucker.
Once you’re done, and you have a pared-down, pruned rose, it’s time to apply mulch. Regular compost mulch can become water-logged so choose something less dense. Popular mulches for roses include woodchips, dry grass clippings and straw. You’re providing a layer of protection for the next few weeks until spring frosts have passed and your rose is ready to come back to life.