Rosa 'Radtko'

Summary

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.

As with most of our roses in previous trials, the highest average overall quality rating for Double Knock Out was on the moderate irrigation level at 50% of ET_o (Table 17a). The highest floral and overall appearance ratings were in May when the first full flush of bloom occurred with all roses achieving the highest possible rating, but the flowering continued throughout the season with the highest rebloom rate on the 50% irrigation treatment in August - not a time roses are typically known to have high numbers of blooms! The plants maintained a good or very good appearance all season on all treatments with no significant differences between treatments. Neither did plants display differences in growth between treatments. The vivid pink blooms fade to pale pink and finally parchment color. They do not hold onto the plant for too long, before shattering and self-cleaning. Foliage appearance was only slightly affected by thrips, but was completely disease-free. This rose has rightly earned its hardy reputation in standard rose trials.

Guests at our Open Houses commented on flower color and “lush green leaves” that contrasted with “beautiful red rose.” At least one individual listed it as their favorite plant of the day. On average, they scored it as very good or good at all three events (Table 17b).