Fact sheet: Double Knockout Rose
The Double Knock Out® Rose
Rosa hybrida ‘Radtko’ PP16202
Varietal Name: ‘demonIntroducer: The Conard-Pyle Co.
Breeder: William Radler, Milwaukee Wisconsin
Type: Landscape Shrub Rose
Zone: USDA 4–10
(Plant 2-3 inches deeper in Zone 4 for best winter survival)
Form: Pointed Ovoid
Color: Cherry Red
Color: Deep cerise, cherry red
Number of Petals: Range18 -24, Average is 20
Diameter: 3 – 3 ½ ” in diameter, average
Fragrance: Light tea rose, slightly spicy
Habit: Compact, mounded and bushy
Inflorescence: 1 to 5 flowers per cluster, up to 25 blooms per flowering branch
Foliage: Deep mossy green with blue and maroon highlights and a maroon underside – distinct glucose appearance
Fall Foliage: Deep, lustrous purple with rich maroon undertones
Disease Tolerance:Totally resistant to rose black spot.
Tolerant of Downy Mildew
Flowering: Continuous from late spring to frost
Height x width: 3-4’ x 3-4’
The Double Knock Out® Rose will find a permanent home in your garden. This absolutely carefree landscape rose has all of the same wonderful characteristics of its sister seedling, Knock Out® with twice as many petals per flower. Fluorescent double, cherry red blossoms attract attention all summer and give way to deep purple fall foliage coloring your garden with three seasons of interest. You don’t have to waste time removing old flowers from this blooming machine. The Double Knock Out® Rose takes the maintenance out of roses. Hardy, drought tolerant upon establishment, this rose is a carefree, show-stopping Star®!
Planted in Nassau County Extension Demonstration Garden