Pruning Knockout Roses: The Simple Rules for Maximum Blooms

Knockout roses (bred by William Radler) are 3–4 ft, self‑cleaning, disease‑resistant shrubs. They don't need fussy pruning—just a few smart cuts.

When

• Late winter / early spring (buds swelling, no new growth).
• Never prune in dormancy (fatal).
• Summer trim okay but reduces vigor.
• Year 1: *no pruning*—let establish.
• Dead/damaged wood: remove anytime.

How

1. Shear or hedge trimmer: cut to ½ height (down to 12″ from base).
2. Shape to ~2 ft below desired height for seasonal blooms.
3. Sterilize tools (alcohol dip).
4. Cut at 45°, slanted toward bush.
5. Remove dead wood first, then long/lean base canes.
6. Water at base (not overhead) in dry spells.
7. Clean bed: remove dried/black canes.
8. 3″ mulch ring (moisture retention, erosion control).
9. Plant in sun, well‑drained soil.
10. Feed with Knockout‑specific fertilizer.

Pro Tip

Dab Elmer's glue on cut cane ends to stop cane borers.

Knockouts are forgiving. Prune confidently, and they'll bloom in waves all season.