This cultivar is listed as triploid in the paper 'Pollen diameter and guard cell length as predictors of ploidy in diverse rose cultivars, species, and breeding lines'
Difficult to imagine from the parentage stated in Modern Roses 10, isn't it? However, if we modify the pollen parent from 'Von Scharnhorst' to 'open-pollinated seedling of Von Scharnhorst' (as stated in the note) then it is quite possible that a very hardy nearby rose in the Experimantal Station played a role.
In Denver Colorado, JP Connell blooms are pale yellow and will have 2-3 flushes during the season. It appears to tolerate some shade and grows in a difficult location, next to the street and under a locust tree. It does suffer some winter die-back. This is a great rose for difficult conditions.
Northwestern Ontario, Canada USDA Zone 2 I have had J.P. Connell in my garden for 7 years - no winter protection - disease free. It was suffering from 4 years of neglect and was rescued late last fall and relocated. This summer she put out numerous sturdy new canes, grew to 4 feet and bloomed well until hard frost. Hopefully next year she'll do even better.
