Another option is developing a Rosa wichurana x R. nitida selection and crossing it with a Rosa wichurana x R. maximowicziana selection to develop a breeding line that perhaps would be more compact in growth than a Rosa wichurana x R. maximowicziana hybrid. Alternatively, (Rosa wichurana x R. maximowicziana) x Rosa nitida would be even more compact and possibily contribute some colour to the fall foliage (there likely wouldn’t be much, if any, if Rosa nitida is only 1/4 of the parentage). Theoretically, the latter would also be cold hardier than the former but there may be a decrease in disease resistance.
David and Paul,
I am not familiar with Rosa maximowicziana, and wonder if you might speculate as to what the species has to offer as a parent. I gather it is similar in many traits to R. muliflora, and rather bristly, but perhaps not overly disease resistant? I like the photos I found of it.
I love to see when others are venturing out into new territory!
Hi Philip,
Great question. It has had extra winter hardiness than the other Synstylae section species that I’ve worked with (at least the clone that I have). Yes, it is quite bristly. I have crossed it with thornless polys and recovered thornless backcrosses with polys or sib matings of F1’s. It has a little gloss to the foliage and the flowers, although fewer in number than multiflora, are larger. There isn’t anything super that stands out to me for the species except the extra winter hardiness. My desire has been to incorporate different genetics into the polyanthas I’ve been working with to eventually hopefully have more genes segregating and different and unique traits emerging. Added winter hardiness is the key trait I’m hoping to get from from this species. The clone I have has some tolerances to diseases, but definitely not clean enough for the average person to be satisfied with without some spray. My hope is that crossing it with R. wichurana descendants that disease resistance would improve.