‘Hazeldean’ sure is a nice bright yellow. I’ve been using its pollen the last two seasons, but admittedly I’ve been only dabbling (since other things have been taking priority over my hybridizing).
So far, I only have two seedlings:
- rugosa X ‘Hazeldean’
which will probably have fertility issues, if it’s anything like rugosa X spinosissima
- ‘Rose de Rescht’ X ‘Hazeldean’
which just sprouted a few weeks back, but already has three true leaves. This could be a very interesting avenue to explore. Although this should be a once-bloomer, it could be a stepping stone toward getting yellow into a hardy repeat blooming old-garden-rose type.
On another note, I’d really like to get a hybrid of ‘Hazeldean’ with the local tetraploids (virginiana and/or carolina), but last year’s pollinations along those lines, weren’t successful. I’ll have to try it again this coming season
Tom
Stefan, yes I agree with you that it’s necessary to go back to breeding at the species or near species to develop disease resistant yellows. One avenue that I will be exploring is to cross ‘Schneezwerg’ x Rosa wichurana and then crossing this breeding line with a breeding line of ‘Hazeldean’ with Rosa laxa and also Rosa beggeriana (there’s likely potential fertility problems with this one). I have seeds stratifying of Rosa laxa x ‘Hazeldean’ from this cross I did last year. Note: Rosa laxa seeds germinate easily.
I like the idea of incorporating Rosa laxa or Rosa beggeriana for toughness and potential disease resistance. If it is true ‘Schneezwerg’ is a Rosa rugosa x Rosa beggeriana hybrid, then I think it’s likely this cultivar gets its extraordinary disease resistance (at least in cold climates) from Rosa beggeriana.
I think it’s essential to get Rosa wichurana in the mix for disease resistance. Note that a ‘Schneezwerg’ x Rosa wichurna breeding line, because it would have white flowers, could easily be painted with yellow. The Rosa rugosa ‘Ottawa’ x Rosa wichurana selection I developed is fertile both ways, so I have proved hybrids between these two species can have good fertility and thus be useful for further breeding.
One drawback of the Rosa rugosa ‘Ottawa’ x Rosa wichurana selection, is that although disease resistant, it is somewhat susceptible to chlorosis. So it remains to be seen if ‘Schneezwerg’ x Rosa wichurana hybrids would also have this problem. But if it does, perhaps reversing the direction of the cross might counter this problem. I guess I should do the cross both ways to save time, in case it was necessary to do it.