Pink Double Knock Out® rose

Rosa 'Radtkopink'

Pink Double Knock Out® rose on Low water in May 2021 at South Coast REC

Summary

South Coast Research & Extension Center (South Coast REC/SCREC) is located in Irvine California, this site has a sandy loam soil and plants are irrigated with reclaimed water. UC Davis is located in Davis, California, this site has a silty clay loam soil and plants are irrigated with potable water. More information about the field sites is located in the Nuts & Bolts section.

Pink Double Knock Out rose, like others in this series, bloomed from April through last data collection in October with the largest show of flowers in May, June, and August in Davis and late May/early June in Irvine. While individual blooms are not particularly well-formed, as a shrub rose, the effect of large numbers of flowers offsets this deficit, especially from a distance. One mark against the flowers is that they tended to hang on the shrub too long after fading and calyces did not clean as quickly as we would have liked. Plant form was also not as consistently uniform and full as other roses in this series we have evaluated.

At both sites there were plants with black spot, though the prevalence was much higher in Irvine where powdery mildew was also an issue with their cooler, more humid summers. In Irvine, plants on both the low and high irrigation treatments were significantly smaller than those on the moderate irrigation treatment, but due to lower flowering scores, diseased foliage, and poor form yielding an overall unacceptable appearance on all irrigation levels, we do not recommend this rose in coastal environments. In Davis, there were no statistical differences between treatments in growth and appearance, but plants were rated modestly better on the moderate level of irrigation.

Basic Info

Submitted by:	Star Roses and Plants
Site(s):	UC Davis & SCREC
Trial Exposure:	Sun
Year evaluated:	2021
Height & Width after 2 yrs:	2.6' x 3.9' - UC Davis 3.25' x 4.4' - SCREC
Reported Height & Width at maturity:	3–4' x 3–4'
WUCOLS plant type:	S
Water Needs & WUCOLS Region:	Moderate
Mean Overall Appearance rating: (1-5 Scale, 5 is highest)	3.7 - UC Davis NR - SCREC
Flowering Months:	April-October - UC Davis April-October - SCREC

Growth and Quality Data

Click Here for Complete Data Set

Pink Double Knock Out 20 June 2021 Close Up

A closeup of Pink Double Knock Out® rose flowers and spent blooms on low water in June 2021.