You prune roses to remove parts of a plant that you don’t want. This pruning leaves room for growth and circulation in the parts of the rose plant that you do want. When you prune roses, you cut the canes (upright branches) of a rosebush. You may cut the canes near the top of the plant, at the base of the plant, or somewhere in the middle, depending on the result you’re trying to achieve.
Here’s the skinny on why you really do want to prune your roses:
To improve flowering: Proper pruning results in more or bigger blooms. Especially with hybrid teas grown for cut flowers, good pruning practices give you huge flowers atop long, strong stems. In general, the further back you cut a rose, the fewer but bigger flowers you’ll get. Prune less, and you get smaller flowers but more of them.
To keep plants healthy: Pruning removes diseased or damaged parts of the plant. It also keeps the plant more open in the center, increasing air circulation and reducing pest problems.
To keep plants in bounds: Without pruning, many rose plants get huge. Pruning keeps them where they’re supposed to be, and it also keeps the flowers at eye level, where you can enjoy them up close.
To direct growth: Pruning can direct growth (and flowers) to a spot you pick. For example, you may prune a climbing rose to direct growth on a trellis.
Whenever you take a pruner to a rose cane, ask yourself why. If you don’t stop to question your pruning, you may not get the effect you want.
Where winter temperatures predictably reach 10°F (–12°C) and lower, wait until after the coldest weather has passed and any winter damage to the plant has already occurred. That’s usually about a month before the average date of the last spring frost — March or April for most people — and coincides nicely with when you remove your winter protection. Your local nursery or cooperative extension office can give you exact frost dates for your area.
In climates where winters are cold or pretty cold (15°F or –9°C and lower), avoid pruning in fall. Any pruning after the first frost but before really cold weather sets in usually signals the plant to grow. New canes or shoots are very tender and cold weather will kill them.
If you live where winters are mild and temperatures rarely dip below 15°F (–9°C), you have to do your pruning earlier because plants start growing earlier. January or February is usually the best time. In areas with very mild winters, rose plants never really go completely dormant or drop all their leaves, so you have to prune with some foliage still on the plant — late December to February are usual times. In such cases, pick off as many of the leaves as possible, but be careful not to damage the bark, which may lead to disease. Removing leaves helps force the plant into dormancy (even roses need a rest now and then) and removes any disease organisms that may be waiting out the winter on the foliage.
You use three types of pruning cuts when pruning roses. Each one generates a very predictable response from the plant. As your pruning prowess grows, you’ll find yourself using a combination of all three types of cuts:
Thinning removes a branch at its origin — that is, it cuts a branch back to another branch or to the base of the plant. Usually, thinning doesn’t result in vigorous growth below the cut. The result of thinning is that the plant is more open and less densely branched. Air circulation improves, which helps prevent disease.
Cutting back a dormant bud stimulates that bud to grow. If you’re pruning during the dormant season — when the rose is resting and leafless in winter — the bud won’t grow until spring, but this type of cut focuses the plant’s energy into that one bud and maybe one or two buds below it. Pruning back to a bud is the best way to direct plant growth and to channel energy into specific canes that you want to bloom.
Shearing is a more aggressive type of pruning but is sometimes effective. Use hedge clippers to whack off a portion of the plant. The result is vigorous growth below the cuts and a denser, fuller plant. Shearing is particularly effective with landscape roses, especially if you plant them as hedges.