Data specific to Roses (Edit)
Bloom size: Medium: 2-3"
Petal count: full: 26-40 petals
Rose bloom color: Medium red
Extra Bloom Info: In clusters
Rebloom: Good
Class: Shrub
Growth Habit: Medium, 3-4 feet, bushy
Fragrance: None
Hybridizer & year: William J. Radler, 2004
Optimal growing zones: USDA zone 4 and warmer

General Plant Information (Edit)
Plant Habit: Shrub
Life cycle: Perennial
Sun Requirements: Full Sun
Soil pH Preferences: Moderately acid (5.6 – 6.0)
Slightly acid (6.1 – 6.5)
Neutral (6.6 – 7.3)
Slightly alkaline (7.4 – 7.8)
Plant Height: 3-4 feet
Plant Spread: 2-3 feet
Leaves: Deciduous
Flowers: Showy
Flower Color: Red
Flower Time: Spring
Summer
Fall
Uses: Cut Flower
Wildlife Attractant: Bees
Propagation: Other methods: Cuttings: Stem
Cuttings: Tip
Miscellaneous: With thorns/spines/prickles/teeth
Awards and Recognitions: Texas Superstar®
Parentage: unnamed seedling x unnamed seedling
Child plants: 6 child plants

Image
Alternative cultivar names:
  • 'Double Knock Out'
  • 'RADtko'

Common names
  • Rose
Also sold as:
  • Double Knockout

Photo Gallery

Date: 2018-05-17
Location: My Garden, Utah
Date: 2013-07-04
4th of July
Location: My Garden in Janesville, WI
Date: 2014-05-19
Location: Botanical Gardens of the State of Georgia...Athens, Ga
Date: 2019-04-17
Knockout Rose 052
Photo by jim1961
Location: Botanical Gardens of the State of Georgia...Athens, Ga
Date: 2017-10-26
Double Knockout Rose 001
Photo by Salems
Location: Botanical Gardens of the State of Georgia...Athens, Ga
Date: 2019-09-22
Red Knockout Rose With Dewdrops 070a
Location: My house in Portsmouth.
Date: 2013-05-12
Location: Breezy Knees garden, York, UK
Date: 2020-09-10
Location: Willow Valley Communities Lakes Campus, Willow Street, Pennsylvania USA
Date: 2019-10-24
Late season bloom
Location: Cedar Creek, Texas
Date: 2020-09-17
Nature is the greatest artist
Location: In my zone 8 garden
Date: 2017-03-20
Location: Central Pa.
Date: August 2018
Double Knockout rose

Date: 2018-05-17
Location: Botanical Gardens of the State of Georgia...Athens, Ga
Date: 2019-04-23
Dew Covered Double Knockout Rose 008
Location: My previous yard in Temple, Texas
Date: 2013
Prolific blooms every season before I moved.
Location: Sherwood Oregon
Date: 2020-05-14
Location: Gause, Texas
Date: 2020-06-09
3rd season in very sandy soil, Central TX.
Location: Rose Garden Center, Tyler, Texas
Date: 2014-05-03
  • Uploaded by jon
Location: Breezy Knees garden, York, UK
Date: 2020-09-10
Photo by stilldew
Location: Gause, Texas
Date: 2020-04-27
2-year plant finally taking off after a 2-year struggle with heat
Location: English Gardens, Dearborn Heights, MI
Date: 2009-05-11
Location: Rose Garden Center, Tyler, Texas
Date: 2014-05-03
  • Uploaded by jon

Date: 2022-05-17
Location: Grapevine, Texas USA
Date: April 17, 2020
Planted Fall 2018

Date: 2013-05-12
Location: My Cincinnati Ohio garden
Date: 2013-06-22
Recent additions to my yard
Location: My garden, Cottage-in-the-Meadow Gardens in South Amana, IA
Date: 2013-06-08
Location: Zone 5b, Chicago suburbs
Date: June 2021
Location: Kalama, Wa.
  • Uploaded by Joy
Photo by Debbie
Location: Botanical Gardens of the State of Georgia...Athens, Ga
Date: 2019-06-23
Double Knockout Rose 011
Location: Wilmington, NC 
Date: 2019-04-08
This years first bloom, from 2 year old shrub which survived hurr

Date: 2018-05-17
Photo by Newyorkrita
Photo by Newyorkrita
Location: My previous back yard in Temple, Texas
Date: 2010
Prolific bloomer every year.
Location: KALAMA WA
  • Uploaded by Joy
Location: KALAMA WA
  • Uploaded by Joy
Location: Allentown, Pennsylvania
Date: 2015-05-30
Location: Massab Acres, Taylor, MI
Date: 2010-07-10
Location: Rose Garden Center, Tyler, Texas
Date: 2014-05-03
  • Uploaded by jon
Location: Rose Garden Center, Tyler, Texas
Date: 2014-05-03
  • Uploaded by jon

Date: 2011-11-10
Location: Middle Tennessee
Date: 2011-10-09
Covered with dew in the morning
Location: At my neighbor's house in Northern KY
Date: 2012-04-22
Location: Grapevine, Texas USA
Date: April 17, 2020
Planted Fall 2018
Location: At my neighbor's house in Hebron, KY
Date: 2012-04-22
Photo by Newyorkrita
Photo by stilldew
Location: Peggy Rockefeller Rose Garden
Date: August
credit: Kelvinsong
Photo by Hamwild

Date: 2018-04-22
Location: Baltimore, MD
Date: 2016-11-16
Location: Baltimore, MD
Date: 2016-05-19
Location: My garden in N E Pa. 
Date: 2008-09-09
Photo by Newyorkrita
Location: Naylor, GA
Date: 2012-03-24
Location: my garden zone 7b NC
Date: 2012-05-28
Location: Barson's Greenhouse, Westland, MI
Date: 2009-08-03
Location: Rose Garden Center, Tyler, Texas
Date: 2014-05-03
  • Uploaded by jon
Location: Middle Tennessee
Date: 2012-04-18
Location: At my neighbor's house in Hebron, KY
Date: 2012-04-22
Location: At my neighbor's house in Hebron, KY
Date: 2012-04-22
Location: At my neighbor's house in Hebron, KY
Date: 2012-04-22

Date: 2013-05-21
Location: Middle Tennessee
Date: 2014-05-14
This plant is tagged in:
Image Image

Comments:
  • Posted by ssgardener (Silver Spring, MD - Zone 7a) on Mar 12, 2013 6:06 AM concerning plant:
    I have this in afternoon sun, maybe 4-5 hours of direct sun. It blooms beautifully, right up until a hard freeze in November.

    Last year the blooms were so heavy and numerous that they flopped over. I don't know whether it's related to not getting full sun, or my poor pruning job in the spring. No more flopping after that first very heavy flush of blooming.

    This is truly a carefree rose. They got a little bit of powdery mildew and black spot during mid-summer heat, but they recovered on their own without being treated. There was a bit of Japanese beetle damage, but no treatment needed for that, either. I give them a little osmocote in the spring and mulch with leaf mold and coffee grounds.
  • Posted by SongofJoy (Clarksville, TN - Zone 6b) on Nov 24, 2011 9:00 AM concerning plant:
    Performs spectacularly here in my zone (6b). Although not fragrant, I planted it next to a fragrant rose to make up for that one shortcoming.
  • Posted by Newyorkrita (North Shore, Long Island, NY ) on Oct 16, 2011 10:54 AM concerning plant:
    No spraying needed on Double Knock Out ever. Plus this rose really does like to bloom a lot. Not as much as the single version though, and if I had to do it over again, I might have gotten the single version Knock Out instead. The blooms on Double Knock Out simply do not fall when done and stay on the shrub in messy brown rotting balls unless I cut them after bloom. So I always do have to prune after blooming if I want it to look attractive.

  • Posted by Debbie (Denham Springs, La. zone 8b - Zone 8b) on Jan 2, 2012 5:38 PM concerning plant:
    Absolutely wonderful plant. After trying about 50 other different types of roses, and growing discouraged because of the diseases associated with Southern grown roses, I finally found a Rose that needs almost no attention. They never have blackspot or rust and in Southern Louisiana humidity, that is a miracle. They should be spaced at least 4 ft apart. They bloom constantly from spring to fall. I was even able to have a vase of roses on my table in November. They actually look like a Hybrid Tea, which I love. What a joy to have blooms all the time . They should be transplanted only in early Spring while they are dormant. I enjoy walking slowly thru my garden and as I walk, I simply snip the older dried up blooms off. (I carry small snips in my pocket). In just a little while, the bushes are all full of blooms again. Love, love this plant!

    How to Prune a Knock Out® Rose by ConardPyle
    Follow these simple steps to prune your Knock Out®
    Step 1: When do I prune my rose bush?
    Prune your rose bush in early spring, never in the fall and never in the winter. Check your rose bush from time to time as spring moves along and when you start to see new shoots growing from the canes on your rose bush, that’s a good sign that it is time to prune.
    Step 2: Use proper tools
    You will need a few basic tools when the time comes to prune your roses: gloves, because of the thorns on your rose bush. Lopping sheers, for some of the heavier canes that are going to be difficult to cut with some of the smaller sheers. Small hand sheers, for some of the finer work, and a pair of hedge trimmers to get the job done quickly.
    Step 3: Determine how high you want to prune
    Determining how high you want to prune depends on how high you want your rose bush to finish. Your rose bush will usually triple in size after pruning so cutting it back to about a foot will leave it at 3 feet when it finishes growing.

« Add a new plant to the database

» Search the Roses Database: by characteristics or by cultivar name

« See the general plant entry for Roses (Rosa)

« Visit the Roses forum

« The Roses Database Front Page

« The Plants Database Front Page

Today's site banner is by dave and is called "Sunroots"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.