RSM J-5 (Marshall, 1973)

Has anyone used Marshall’s J-5 to create repeat blooming yellow/peach seedlings? I’m loaded up with pollen right now and I’m thinking about trying it on some yellow breeders with a known history.

I guess I’ll just try it and see what I get! Brace yourself, 1-72-1!

I saw your post and thought about it, but had nothing to add. Looking at the lineage of the Morden yellows, it gets a little confusing. For example, they add Rosa foetida bicolor back in later, but the rest is mostly the same admixture of arkansas and floris, etc. Until they use Sunsprite. So why did they repeat the process many times after J-5? That is what I wondered when considering your post.

I bought Morden Sunrise for $5 this spring from Ho d’Pot, just to see and likely cull it later. Definitely short on petals and a little light. The vigor is way above average. I am sure it will eventually BS, but I could see the potential of using it.

J5 itself has pretty foliage. If one uses it, it would be a shame to lose that. I think there is potential in use any of these, but probably with roses more compact and probably with the need to reinforce BS resistances.