It is not disease resistant, and will get blackspot.

You are going to really enjoy this rose, but I'm afraid Diane is right.
In order to get the most out of this rose you may have to spray. I find that the effort to keep this clean is well rewarded.
Helmut

Here is a link that might be useful: Rainbow's End

One of my favorite roses. Excellent container rose with a nice rounded decorative bush shape. Blooms exceptionally well in the spring and fall. In my garden it has the good sense not to bloom as much in the middle of summer when I would have to go out in the inferno to deadhead. Suites me just fine. Only in the movies does one see faultless rose petals scattered around. In real life most roses need to be sprayed if you are in an area with a long growing season (such as Kentucky). I do spray, but must say that my Rainbow's End (placed in an area with excellent wind circulation and far removed from other blackspotters) does not seem particularly prone to B.S. if I happen to miss spraying it occasionally.

I love the flowers of this rose. I even won my only Mini Queen with it several years ago. Unfortunately I could not control blackspot :-( so I replaced it with Hot Tamale and that rose is doing much better (I spray with fungicides too).

Now that just goes to show you. I had Hot Tamale and Rainbow's End side by side in containers. Their colors are fairly similar. Hot Tamale was one of the first to blackspot for me, while Rainbow's End remained her usual clean self. Both received equal spray treatments, water, etc. In my case I said goodbye to Hot Tamale and kept Rainbow's End. Maybe we have different strains of B.S. or maybe that's just life in the rose world.

I have both Rainbows end and cl. Rainbows end I find the climber has less blackspot! I do spray but got a bit sloppy last year. I haven't started spraying yet this year and the reg. R. E. is getting spotty ,while the climber looks fine!
Lee