How to Prune Roses: When to Cut and How Hard

When to prune

The main prune goes in at the end of dormancy, as the buds begin to swell but before they break into leaf. In practice that means late winter to very early spring in most gardens. Prune much earlier and a mild spell pushes soft growth that the next frost kills; prune much later and you waste energy the plant has already spent pushing leaves you are about to remove.

There is a second, lighter round in autumn that is not really pruning: shortening the tallest canes by about a third on tall bush roses so wind cannot rock them through winter. Leave the real cutting until late winter, when you can see which wood came through and which did not.

Once flowering roses, which bloom on wood made the previous year, are the exception: prune those straight after they finish flowering in summer, not in late winter, or you cut off the flowers before they open.

The cut itself

Every pruning cut on a rose follows the same rules regardless of type. Get these right and the plant heals fast and grows in the direction you want. Get them wrong and you leave stubs that die back and become entry points for canker.

1. Use sharp, clean pruners Blunt blades crush the stem instead of slicing it, and crushed tissue dies back. Sharpen before you start and wipe the blades between plants.
2. Cut a quarter inch above an outward facing bud Any closer and the bud dries out; any further and you leave a stub that dies. Choosing an outward facing bud sends the new shoot away from the center.
3. Slope the cut away from the bud A gentle slope running down away from the bud sheds water off it. A cut sloping towards the bud drains straight into it.
4. Cut back to white pith Look at the cut face. Brown or gray pith in the center means dead wood, so keep cutting lower until the exposed pith is clean and white.
5. Use loppers or a saw on old wood Anything thicker than about half an inch (12 mm) is beyond pruners. Forcing it twists the blades and tears the bark.

Prune out the three D's first on every rose, whatever its type: dead, damaged and diseased wood. What is left is a much easier decision.

How hard to cut a bush rose

On a bush rose, how hard you prune sets the trade off between the number of flowers and their size. Hard pruning to three or four buds produces fewer, larger blooms on strong stems, which is what exhibitors want. Light pruning to about half the height gives more flowers, smaller, on a bigger plant.

The middle course suits most gardens: cut the whole bush back by roughly half, remove any cane thinner than a pencil, and take out one or two of the oldest, woodiest canes right at the base to make room for new growth from the crown. Aim to leave an open, goblet shaped framework of four or five strong canes.

Never take more than about a third of the total growth off a shrub rose in one go unless you are deliberately renovating. Shrub types resent hard pruning far more than bedding types do.

Climbers and ramblers are pruned differently

This is where most rose pruning goes wrong, because the two are usually pruned as if they were the same plant. A climber repeat flowers on short side shoots off a permanent framework, so you keep the framework and shorten the side shoots. A rambler flowers once, on wood made the previous year, so you cut out whole old canes and keep the new ones.

On a climber, tie the main stems as close to horizontal as the wall allows. A stem trained sideways breaks buds along its whole length; the same stem trained straight up flowers only at the top, which is why so many climbers end up bare at the bottom with a few blooms out of reach.

If you cannot tell which you have, watch it for one season. A rose that gives one enormous flush of small flowers in early summer and then nothing is a rambler. One that flowers on and off with larger blooms is a climber.

Renovating a neglected rose

An old bush that has become a thicket of thin, twiggy growth with flowers only at the top can usually be brought back, but not in one season. Cutting the whole thing to the ground in one go often kills a rose that is already weak, or produces a mass of soft growth that cannot support itself.

Spread it over three years. Each late winter, take out a third of the oldest canes right at the base and shorten the rest, so the plant is rebuilt from new growth from the crown while never losing more than a third of its leaf area at once. Feed and mulch generously through those three years, because renovation is expensive for the plant.

1. Year one: clear and open Remove everything dead, diseased or crossing, plus the single oldest, thickest cane cut to the base. Shorten what remains by about a third.
2. Year two: replace again Take out the next oldest cane at the base and keep the strongest of the new shoots that came from the crown last season.
3. Year three: settle the shape Remove the last of the original old wood and prune what is left as a normal bush. From here it is on the standard cycle.
4. Feed through the whole process Mulch each spring and feed at bud break and after the first flush. A rose being rebuilt cannot fund new canes out of tired roots on its own.

Note down which canes you removed and roughly where, each year. In year two it is surprisingly hard to remember which wood was original and which was the replacement you were meant to keep.