Sorry to say that maturation doesn't affect resistance. Either its there from the beginning or not.

wanttogarden, I'd imagine this is a terrible year for disease where you are as it is AWFUL here north of Los Angeles. I'm seeing rust, black spot and mildew on things which I've never seen them on before. Perhaps, you should continue trying to grow these roses to the best of your ability and permit them to settle in to see if it improves? There are two schools of thought on resistance. One states it is resistant or it isn't. From experience, many roses do improve as they mature. It appears their immune systems kick in better when they develop the root systems they are supposed to have. Newly planted bare roots and newly planted canned roses can't have all the root system they should have for a season or two. Personally, I'd play it wait and see. If they're rusting for you now where they are, they aren't going to "infect" your other roses. They're rusting because the conditions are right and the spores are already there. What is going to rust is going to whether or not these two new roses are there. You're in a great position to experiment and determine whether you observe them improving or not with time. Good luck and enjoy them. Kim

Thanks guys.

I really love them. I guess I have to live with them some how. Next year, I will prune them at the end of Feb. not Jan and spray them with copper.

For now, I cannot do anything until rains stops next week. Maybe then I defoliate them again and spray with copper.

Thanks for words of advice and encouragement.

FJ

Thanks guys.

I really love them. I guess I have to live with them some how. Next year, I will prune them at the end of Feb. not Jan and spray them with copper.

For now, I cannot do anything until rains stops next week. Maybe then I defoliate them again and spray with copper.

Thanks for words of advice and encouragement.

FJ

That's kind of a surprise about 'Eureka'. Mine is really clean. It's a very bad year for rust.

Some years a single well-timed spray of a real fungicide (Banner Maxx) can do wonders.

There has been recent work that's rather discouraging on the multiple kinds of funal infections: multiple strains of Black Spot and multiple strains of Powdery Mildew.

The link below is to a much older paper on Rose Rusts and it reports (you guessed it) multiple strains of Rose rusts, some of which are not infective of some species of roses.

What you might want to note is when do the uredospores emerge? Those are the larger black speckles on the undersides of leaves. They aren't there all the time. All that orange stuff is another kind of spore and the orange stuff doesn't carry the disease from one season to the next. What you want is to prevent uredospore appearances because those are the ones that carry the disease into the next year.

So far, rust isn't a problem near me. I've seen it at Hershey PA, so I know it can exist and propagate in the east, BUT so far no one seems to spreading it around in my part of the country.

Here is a link that might be useful: Rose Rusts

I live near Sacramento, probably hotter than your climate. HOE never got rust here. Maybe you could move it to a different spot?
I got rid of Abraham Darby only because of rust it got every year. I have a low tolerance for disease prone roses, as we should not have to put up with that in our climate.
I do, however, expect lots of fungus this spring as this is the wettest spring since a memorable El Nino spring years ago, when blackspot (what's that?) was rampant.
As to HOE, I haven't been able to find a good place for it. It has been from pot to ground to pot. It just may be too hot in my climate for it. I haven't given up yet, as it has no disease here.
I do hate rust!

No. Rust resistance, or at least the incidence rate of rust, will actually decrease as the roses mature.

Since rust is partially caused/exacerbated by humidity and poor air circulation, a mature rose bush with many more leaves and density of structure, will be all that more prone to rust infection. Secondly, once rust spores infect an area, they are very difficult to get rid of and will tend to reinfest the same rust prone varieties year after year.

FWIW -- MILDEW resistance actually does seem to increase as a plant matures. But -- RUST . . . ICK.

Of course, your environmental conditions ... THOSE may alter.
We're having a remarkably strange spring, all up and down California.
In a different, more benign year, things might be better.
(Or not.)

Jeri

For what it is worth, it has not been my experience that disease resistance improves with age on any rose. For me, once a mildew magnet, always a mildew magnet. And the same goes for rust.

Although I will say this is quite a bad year for rust and not so bad for mildew, so other years may be different, weather-wise.

I live in a completely different zone, much more humid and with a full winter, so what has worked for me may be of little use. However, I have successfully eliminated rust on affected varities by pruning them to the ground in winter and letting the rose send new basals up. When I haven't, the rust returns next season. The rust seems to overwinter on the canes. I use no chemicals.

Steve