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UC Master Gardeners of San Luis Obispo County

Pruning Rose Bushes

Pruning Roses: A Home Gardener’s Guide

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 overall health and stimulates new growth for larger blooms and a more attractive plant. Removing dead, damaged, 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 late winter. In San Luis Obispo County, this is December–January for coastal areas and January–February for inland areas. Weather conditions may affect timing. Prune before spring growth begins, while the plant is dormant. In mild winter areas, old leaves may remain, but if there is no new growth, the plant is dormant.

Once-blooming roses such as ramblers and some climbers bloom on old wood and should be pruned after their spring bloom, or you will remove this year’s flowers.

Most rose bushes consist of a rootstock variety grafted with a desirable flowering variety. Identify the graft union. Anything growing below it is a “sucker.”

Equipment You'll Need

  • Gauntlet-style gloves for protection
  • Bypass shears (not anvil style), one handheld and one long-handled
  • Nippers or scissors for removing leaves
  • Heavy long sleeves (avoid sweaters)
  • Safety glasses or goggles
  • Lysol or 70% alcohol for tool sanitation
  • Container for pruned plant material

Basic Pruning Steps

  1. Trim back old growth by about one-third. Overgrown bushes may be cut back up to one-half. Sterilize 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 to expose structure and remove overwintering pests. Cut leaves off; do not strip them.
  3. Remove the “four D’s”: dead, dying, damaged, and diseased stems back to the base. Dead wood is brown; living wood is green. Remove shriveled stems, black canker, cracks, and split stems.
  4. Remove suckers growing below the graft union as close to the root stem as possible.
  5. Open the center to create a vase shape with upward branches. In hot summer areas, leave some interior growth to shade the graft and prevent sunscald.
  6. Remove thin, weak growth thinner than a pencil.
  7. Cut remaining canes back to healthy white center tissue.
  8. Make cuts 1/8–1/4” above an outward-facing bud to encourage outward growth. A 45° angle helps water run off, but straight cuts are acceptable. Do not seal cuts.
  9. Clean up and discard all plant debris to reduce disease and pests.

Post-Pruning Care

  • Apply horticultural oil while dormant to smother overwintering pests.
  • Use copper spray to prevent fungal disease if needed.
  • Apply 2–3 inches of mulch, keeping it away from the base.
  • Four weeks after pruning, fertilize prior to rainfall or water deeply.

Pruning FAQs

Pruning Height

Prune one foot lower than your desired full-foliage height. Lower pruning (especially hybrid teas) produces longer stems and larger blooms. Taller bushes produce smaller but more numerous flowers.

Pruning Climbing Roses

Climbing roses have main (vertical) canes and lateral canes. Lateral canes produce flowers. Prune laterals to shape and encourage blooms. Do not cut main cane tips on young climbers until desired height is reached. As new main canes develop, remove an equal number of old ones to renew the bush.

Knock Out, English, and Shrub Roses

Prune after the second or third year at the same time as other roses. They bloom on new growth. Remove old, dead, diseased canes to the base and prune back by one-third for shape. Deadhead and remove rose hips after the first bloom to maintain flowering.

Summer Pruning

Deadhead spent flowers above a node at any time during the blooming season to encourage reblooming and maintain appearance.

Rose Hips and Dormancy

In moderate climates, roses may need help entering dormancy. In fall, stop deadheading final blooms. Remove petals and allow hips to form and remain through winter to signal dormancy.

References