Well, the seedlings of the F1 generation are, as always and also in this case, a compromise between father and mother, because the hereditary traits of both parents are located unchanged next to each other. It is a kind of mechanical mix, so sometimes it is rather difficult to see clear demarcations. Mostly, the dominant traits show up, the recessive ones remain hidden until a second generation. Sometimes you’re lucky and you will find a desirable recessive characteristic already in the F1. When the OGR genes predominate, the rose will be summer-flowering and does not bloom in the first year. If the influence of R.chinensis is stronger, which is more sporadic, the seedling will be flowering already in the first year and will be repeating throughout the season.
There are also some hybrids that do not bloom in the first year but are good repeaters from that point in the second year. Of course, the growth type also varies greatly. My experience has shown that the typical Portland habit (short-stemmed flowers and straight, compact growth) are recessive traits because the growth habit of the other parent often predominates. With a greater proportion of R. chinensis influence, I sometimes see a heavy susceptibility to powdery mildew, a continued cultivation is not really advisable in this case. Most of the time, an intense susceptibility persists, while mild susceptibilities disappear. In general, the development of these hybrids needs a little more patience and observation. It can be said that each breeding year contains only a very few seedlings remaining, which embody a good balance of both parent strains and are worth going through further selections. Therefore it is always a challenge to find the best compatible mix between OGRs and Modern Roses by choosing the right genetic material, but I’m happy to do the job year by year.
The second seedling of ‘Rose de Rescht’ X ‘The Squire’, 2022 did not bloom until now. It is clearly much more tender in growth and habit as the sibling of the year 2017 but is still in the selection process.
Regarding some further examples I would like to refer you to: