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Double Knock Out (Rosa 'Double Knock Out'), whole plant
  • Double Knock Out — close-up of leaves and flowers
  • Double Knock Out — seasonal appearance
  • Double Knock Out in a garden setting

Double Knock Out

Rosa 'Double Knock Out'

Easy · Beginner friendly

About Double Knock Out

Double Knock Out is a fully double-flowered version of the original Knock Out, producing clusters of 3-inch fully double cherry-red blooms with the same disease resistance and continuous bloom on a 3 to 4 foot rounded bush. Introduced in 2004, it gives American gardeners the low-maintenance landscape rose experience with more traditional rose-shaped flowers.

  • Disease-resistant
  • Low-maintenance
  • Long-blooming
WATER
Regular
Top inch dry
LIGHT
Full sun
6+ hrs direct
HARDY
Hardy to -30°F (-34°C)
USDA hardiness zones 4–10

How to care for Double Knock Out

Watering

  • Springevery 7 days
  • Summerevery 5 days
  • Fallevery 10 days
  • Winterevery 21 days

Soil · Rich & loamy

  • Top dressingBark mulch15%
  • Main mixRich loam + compost 3:170%
  • DrainageGravel15%

Use fully finished compost — fresh compost burns roots.

FERTILIZER

Balanced Feed 14-14-14

An even feed covers all three needs at once, keeping leaves, roots and blooms moving together with nothing pushed out of balance.

N33%P33%K33%
  • Nitrogen · Leaves
  • Phosphorus · Roots + Blooms
  • Potassium · Strength
  • Springevery 45 days
  • Summerevery 45 days
Get watering reminders for Double Knock Out — free on iPhoneDownload on the App Store

At a Glance

  • NativeNorth America
  • Height3–4 ft (0.9–1.2 m)
  • Spread3–4 ft (0.9–1.2 m)
  • Flower colorRed
  • Foliage colorGreen, Bronze
  • SoilLoamy, Well-drained, Rich
  • LocationsYard

Bloom time

BLOOM CYCLE

Peak bloom

May–Sep

J
F
M
A
M
J
J
A
S
O
N
D

Self-cleaning, no deadheading required; prune hard in late winter

Fragrance

LIGHT FRAGRANCE

The flowers have a light scent.

Toxicity

Humans Slight

Unknown toxic principle

Slight

  • Stem
  • Contact

EXPOSURE Touching stems.

EFFECT Pricks from thorns.

NOTE Not toxic; thorns cause mechanical injury.

Safe

EXPOSURE No exposure route is reported.

EFFECT No toxic effect is reported.

NOTE Listed as non-toxic for dogs; avoid eating ornamental plants unless confirmed edible.

Safe

EXPOSURE No exposure route is reported.

EFFECT No toxic effect is reported.

NOTE Listed as non-toxic for cats; avoid eating ornamental plants unless confirmed edible.

Educational information, not medical or veterinary advice. If exposure is suspected, contact a doctor or veterinarian.

DISTRIBUTION

Double Knock Out · Native
  • Native
  • North America

History

Illustrated historical scene for Double Knock Out

Rosa 'Double Knock Out' is a fully double cherry-red shrub rose bred by William J. Radler and released by Conard-Pyle in 2004 from an unnamed seedling crossed with 'Knock Out'. The cultivar was developed to answer one of the commonest criticisms of the original 'Knock Out': its single semi-double flowers, while prolific, lacked the classic full rose form many gardeners wanted. 'Double Knock Out' retained the breakthrough disease resistance, continuous self-cleaning bloom, and cold hardiness of its parent while producing thirty-petal fully double cherry-red blooms reminiscent of old-fashioned roses.

It quickly joined 'Knock Out' as a top-selling landscape rose, and the Knock Out family now includes pink, blush pink, yellow, coral, rainbow, and white sports marketed under the same series name. Brought traditional rose flower form to the iconic Knock Out platform, expanding the family and further cementing Knock Out's dominance of the American landscape rose market.

Symbolism & meaning

What It Symbolizes

Double Knock Out Rose is double resilience — fully petalled blooms wrapped in genuine disease resistance, the modern shrub rose that finally let casual gardeners grow roses without spray bottles. It honors classic rose form while wearing modern toughness, a heritage shape on a contemporary constitution. It is proof that resilience and beauty are not at odds, and that gardening can be made easier without becoming dull.

  • Double resilience — double flowers with disease resistance
  • Classic form — traditional rose shape, modern toughness

Where the Name Comes From

Named for its fully double flower form compared to the original semi-double Knock Out.

Uses & Fun Facts

  • Disease-resistant cherry-red shrubs form low maintenance flowering hedges
  • Continuous bloom mass-planted in foundation beds and parking islands

Related plants

More Rosa plants

Plants with similar care

Frequently asked questions

How often should I water Double Knock Out?

In summer, water about every 5 days; in winter, about every 21 days. Adjust for heat, pot size and drainage.

How much light does Double Knock Out need?

Full sun: 6+ hrs direct. Watch the leaves — scorching or stretching means the light needs adjusting.

Is Double Knock Out toxic to cats or dogs?

Pets Safe (Dogs Safe · Cats Safe) Educational information, not medical or veterinary advice. If exposure is suspected, contact a doctor or veterinarian.

Is Double Knock Out easy to grow?

Yes — it is considered an easy, beginner-friendly plant.

When does Double Knock Out bloom?

It typically blooms May–Sep in the Northern Hemisphere.

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