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'RADtko' rose Description
'RADtko' rose photo
Photo courtesy of MMastnak
Commercially available
HMF Ratings:
41 favorite votes.  
Average rating: GOOD+.  
Medium red Shrub.
Registration name: RADtko
Exhibition name: Double Knock Out ®
Bred by William J. Radler (United States, 1992).
Introduced in United States by Conard-Pyle (Star Roses) in 2004.
Introduced in Australia by Corporate Roses Pty. Ltd. in 2011 as 'Double Knock Out'.
Red.  Mild, cinnamon, spice fragrance.  up to 23 petals.  Average diameter 3.25".  Medium to large, double (17-25 petals), in small clusters bloom form.  Blooms in flushes throughout the season.  
Medium, bushy, rounded, spreading, upright.  Small, semi-glossy, medium green, dense, leathery foliage.  3 to 7 leaflets.  

Height: 3' to 4' (90 to 120cm).  Width: up to 39" (up to 100cm).
USDA zone 4a through 9b.  Can be used for beds and borders, garden or landscape.  Disease susceptibility: very blackspot resistant..  Remove spent blooms to encourage re-bloom.  Spring Pruning: Remove old canes and dead or diseased wood and cut back canes that cross. In warmer climates, cut back the remaining canes by about one-third. In colder areas, you'll probably find you'll have to prune a little more than that.  
Canada - Patent No: 3104  on  4 Jan 2008
Application No: 04-4297  on  9 Jul 2004
Breeder: William J. Radler, Greenfield, United States of America
'Radtko' was selected in June 1993 from a seedling population produced by a controlled cross of 'Carefree Beauty' as the female parent and 'Razzle Dazzle' as the male parent, in Greenfield, Wisconsin, USA in June 1992.
United States - Patent No: PP 16,202  on  10 Jan 2006   VIEW USPTO PATENT
Application No: 10/873,196  on  23 Jun 2004
The female parent (i.e., the seed parent) was a seedling of the ‘Bucbi’ variety (U.S. Plant Pat. No. 4,225). The ‘Bucbi’ variety is marketed under the CAREFREE BEAUTY trademark. The male parent (i.e., the pollen parent) of the new variety was a seedling of the ‘Razzle Dazzle’ variety (U.S. Plant Pat. No. 3,995). ...The rose plants of the new variety illustrated herein were approximately five years of age and were observed during mid-May, 2004, while growing outdoors near West Grove, Pa., U.S.A.
Additional info: The Knockout Rose

Parentage as per breeder's description of 'Knock Out' which according to the patent has the same parentage. Seedling numbers in post by Will Radler on May 29, 2017 re Cancan: Seedling 93-104.3 described as sister seedling of 'Double Knock Out', i.e. 85-139.1 x 84.196.8.

Ploidy supplied by David Zlesak. Different ploidy stated in 2023 reference.