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Sunny Knock Out® Rose

Rosa 'Radsunny'

Rosa ‘Sunny Knock Out’ on 20% ETo on May 1, 2017. Photo: SK Reid.
Rosa ‘Sunny Knock Out’ on 20% ETo on May 1, 2017. Photo: SK Reid.

Summary

Foliage damage from aphids, thrips, and some powdery mildew were the main detriments to the appearance of this yellow shrub rose. The plant was good at self-cleaning spent blossoms and maintained a mostly uniformly rounded habit with an occasional horizontal branch thrown out near the base of the plant. Flowering was high in late April to May, with the highest rebloom percentage averaging 50% coverage on the 50% ETo treatment (Table 16a). Unfortunately, with low mid-season flowering rates, the foliage needed to carry the appearance of the shrub. After July, only the 50% irrigation treatment had acceptable average foliage ratings. With average flowering between 20 to 50% coverage, the plants on 50% of ETo therefore averaged the best overall appearance ratings. There were no significant differences in growth between treatments.

This was one of the most discussed roses in the comment forms in the spring Open House event. Many listed this as their favorite plant, with some ascribing it the title “Best rose in the field.” The flowers, both their initial yellow color (“love the bright yellow!”) and their “change from yellow to white” were positively received by participants. Also noted was their scent and perceived “pollinator friend[liness]” due to the open, single nature of the flower. While scores did decline in subsequent open houses, this could be due to the bloom pattern of the cultivar (Table 16b). This cultivar put on a spectacular show with its initial bloom, then transitioned to a more subdued blooming pattern, always retaining a few flowers on the plant rather than cycling in and out of bloom in a boom and bust fashion. Overall, many continued to list this cultivar as their favorite plant and one they would recommend. One participant perfectly summed up the zeitgeist of Sunny Knock Out with the comment: “I am not a rose person, but this was lovely.”

Rosa ‘Sunny Knock Out’ on 50% ETo in September 2017. Photo: SK Reid.
Rosa ‘Sunny Knock Out’ on 50% ETo in September 2017. Photo: SK Reid.

Basic Info

Submitted by: Star Roses & Plants
Trial Exposure: Sun
Year evaluated: 2017
Height & Width
(after 2 years):
31" x 50" - UC Davis
Reported Height & Width
(at maturity):
3-4' x 3-5'
WUCOLS plant type: S
Water Needs & WUCOLS Region:
Low - Region 2 
Mean Overall 
Appearance rating:
(1-5 Scale, 5 is highest)
3.4 - UC Davis 
Flowering Months
May-October - UC Davis

Growth and Quality Data

Click Here for Complete Data Set

Rosa ‘Sunny Knock Out’ on 50% ETo (the recommended treatment) in July 2017. Photo: SK Reid.
Rosa ‘Sunny Knock Out’ on 50% ETo (the recommended treatment) in July 2017. Photo: SK Reid.

Rosa ‘Sunny Knock Out’ on 20% ETo in October 2017 (September photo unavailable). Photo: SK Reid.
Rosa ‘Sunny Knock Out’ on 20% ETo in October 2017 (September photo unavailable). Photo: SK Reid.

Rosa ‘Sunny Knock Out’ on 80% ETo in September 2017. Photo: SK Reid.
Rosa ‘Sunny Knock Out’ on 80% ETo in September 2017. Photo: SK Reid.