That’s really cool Andrea!
Even if it’s slow growing I’d be sure to keep that one.
I have a little rosa Bracteata in a pot too. This bracteata is a young plant. This summer my bracteata doesn`t grow very well.
It´s has very small leaves, the growth of my Bracteata is similar as the Bracteata-seedling.
I think the bracteata and the seedling need more fertilizer.
Now, the seedling grows better after I fed it. I think it needs a lots of fertilizer.
In a few month we will have winter. I don´t know if this wichuriana-bracteata seedling will survive snow and frost.
Does anybody have experience ? I live in Germany.
I think the general rule is that hardiness is proportional to the average from that of the parents. Of course people select for things that violate the general rule. That’s how we get hardier roses with some tender strains mixed in. But if you assume that bracteata can tolerate 0 C, and wichurana tolerates -15 C you might expect somewhere between -5 and -10 as the likely limit. Very likely there are particular strains of each species in their native range of distribution where they are more or less hardy than the average of the species. That is certainly true of other woody shrubs among the rosaceae. But if you know the hardiness of what strains you start with, based on actual experience, you can guess their offspring’s behavior fairly well.
Remember that snow is a very good insulator. Also dry leaves or straw works well. In my garden plants other than roses survive despite -15 to 20 C nominal air temperature, while under leaf and snow cover, when they are listed as not tolerating freezing. The soil does not freeze because our most extreme cold does not last many days. Often these years it is only a few hours on a few nights.
So it depends a lot which part of Germany you are in, how much the North Sea tempers your climate, whether you are up in mountains, or in a city. If cabbages or arugula or spinach can winter over, it is not very cold, no more than about -10 mostly. They will tolerate that much cold , or somewhat more if protected.