Pruning Rose Bushes

By Lisa Mowery, UC Master Gardener

The home gardener can have beautiful healthy rose bushes by following a few basic pruning rules.

Why do you need to prune?

Annual pruning improves the overall health of the rose bush and stimulates new growth for larger blooms and an attractive plant. Removing dead, damaged, or diseased canes and dense growth reduces the risk of fungal infections and pests.

When to Prune Roses

The best time to prune most roses is in late winter. In SLO County, this is December-January for coastal areas, January-February for inland areas. Weather can affect the best pruning time. Prune before the start of spring growth when your plant is dormant. In mild winter areas, there may still be old leaves on the bush, but if there is no new growth, it is dormant.

Once-blooming roses like ramblers and some climbers bloom on old wood and should be pruned AFTER their spring bloom or you’ll prune off this year’s buds and flowers.

Most rose bushes are a combination of a rootstock variety grafted with a desirable rose flower variety. Identify the graft union on your bush, and where the canes of your rose variety grow above that graft. Anything growing below the graft is a “sucker.”

Equipment You'll Need

Good gloves – Gauntlet‑style recommended for extra protection.

Bypass shears, not anvil style- One handheld and one long handled.

Nippers or scissors to cut off leaves.

Heavy long sleeves -don’t wear a sweater.

Safety glasses or goggles for eye protection.

Lysol or 70% alcohol for cleaning pruners in a sprayer or small bucket

A container for the pruned off plant material.

Basic Pruning Steps

1. Trim back old growth by about one‑third. If a bush is overgrown or hasn’t been pruned regularly you can trim it up to ½. Sterilize your pruners between plants with 10% bleach solution (9 parts water to 1 part bleach), 70% alcohol or full-strength Lysol.
2. Remove all remaining leaves. This allows you to see the structure of the bush and canes while removing any pests or diseases that may be over- wintering in the foliage. Don’t strip them off, cut them off with the little nippers.
3. Start by cutting out the ‘four D’s’ – remove any dead, dying, damaged and diseased stems back to the base.Dead wood is brown, green is living. Look for shriveled stems, black canker areas, cracks, split stems. Wood damage caused by crossing branches can serve as an entry point for disease so prune these out.
4. Cut off suckers growing below the graft union as close to the root stem as you can.
5. Open the center of the plant to create a vase-like shape with upward branches. If you live in a hot summer area and the shrub gets full sun all day, leave some branches in the center to shade the root graft and prevent sunscald.
6. Remove any thin, weak growth thinner than a pencil. It will never get thicker or stronger.
7. Prune the remaining canes until healthy, white center is revealed in each cane.
8. Prune by cutting 1/8” to 1/4” above an outward‑facing bud to encourage outward growth. Cuts made at a 45‑degree angle sloping away from the bud, will allow water to run off. It’s OK to cut them straight across, especially if the cane doesn’t stand straight up. It’s not necessary to seal the cuts.
9. Clean up, removing and discarding all plant debris to prevent disease or pests.

Post-Pruning Care

Consider applying horticultural oil after pruning while the rose is dormant.  Oils smother overwintering scales and insect eggs; they are also the least harmful products to beneficial insects. This is also a good time to use a copper spray to prevent fungal disease.

Apply a layer of mulch at least 2‑3 inches deep, keeping it away from the base of the plant.

Four weeks after pruning, apply a fertilizer recommended for roses just prior to rainfall, or water deeply after application.

Pruning FAQs

Pruning height:

Prune your rose bush a foot lower than you want it to be in full foliage, keeping the canes at a consistent height. The lower you prune (especially hybrid teas) the longer the stem and bigger the blooms. If the rosebush is kept taller, it will produce smaller but more numerous flowers.

Pruning Climbing roses:

Climbing roses have 2 types of canes, main and lateral. The main (vertical) canes come directly from the base and give the plant its height. Growing out of the main canes are the lateral canes which produce the flowers. Pruning the lateral canes encourages blooming and can be done anytime of the year to shape the plant. Prune to shape the plant, don’t worry about pruning to outward‑facing buds. Don’t prune back the growing tip of main canes on young climbers until they reach the desired height. As your climber puts out new main canes, prune out an equal number of old ones to renew the bush.

Knock Out, English, and Shrub Roses:    

Knock out roses can be pruned after their second or third year at the same time as other roses. They bloom on new growth, so cut old, dead, diseased canes to the base. The plant can be pruned back 1/3 of its height to achieve the desired shape and size. To maintain blooming, deadhead, remove developing rose hips and trim back after first bloom.

Summer Pruning:                        

Spent flowers can be cut back anywhere along the stem just above a node, at any time during the flowering season, on any type of rose. This “deadheading” will encourage more blooms on reblooming roses and maintain an attractive rose bush.

Rose hips and dormancy:

In our moderate climate, roses may need help to go dormant. In the fall, do not deadhead the final blooms but remove the petals and allow the rose hips to develop. Leave the rose hips on through the fall and winter; they will tell the rose to go dormant.

References

Pushies, Barbara. Pruning Roses and Cultivating Beauty. UC Master Gardener Program Statewide Blog. 2024. Pruning Roses and Cultivating Beauty - UC Master Gardener Program Statewide Blog - ANR Blogs (ucanr.edu)

Rose Pruning and Care. Master Gardener Program of Yolo County. 2019. 366446.pdf (ucanr.edu)

Rose Pruning Non-Tip. UC Master Gardener Program of Contra Costa County. 2018. Rose Pruning "Non-Tip" - HOrT COCO-UC Master Gardener Program of Contra Costa - ANR Blogs (ucanr.edu)

Remove Suckers from Roses. UC Master Gardeners of San Luis Obispo YouTube.  2022. How to Remove Suckers from Roses - YouTube