Mildew Resistance

I stratified/germinated all of my seedlings outdoors this season. Mildew has just recently struck them, and is affecting just about every kind of seedling I have, to some degree.


rugosa X spinosissima

rugosa X Hazeldean

arvensis X rugosa

Unknown damask X Carefree Sunshine

Cherry Meidiland X William Lobb

(Bracteata x (rugosa X palustris)) X OP

(Fragrant Cloud x Rosa carolina) X Carefree Sunshine

I have one seedling (the fastest growing one) from the last batch that is completely unaffected. I have read of seedlings being susceptible to mildew and outgrowing that susceptibility as they mature. What I’m wondering is, would this seedling be resistant just because it is bigger than its siblings? Or does this look like a case of a truly mildew-resistant plant.

Once again, the picture is there sometimes, and other times not, so here is a link:


Hi Tom:

That clean one looks real good. While it may be true that immature seedlings can outgrow their tendancy to mildew, there are plenty of seedlings that are clean of powdery mildew from the start. I suspect that ‘Carefree Sunshine’ is giving you the cleanliness. I have noted that ‘Baby Love’ and seedlings of ‘Baby Love’ are the best in my experience with passing along powdery mildew resistance, and it is a strong trait.

Jim Sproul

I’m not so sure about Carefree Sunshine and mildew resistance, since mine got mildew. Impressive seedling!

Lloyd Center Supreme is my most mildew resistant seedling parent that I have. Parentage given by the breeder was Brion x Silver Jubilee. This large-flowered variety seems to give even thicker, more disease resistant foliage that the other “large-flowered kordesii relations” that I grow.

That plant looks resistant. Regardless of the size of the plant, it would mildew if it were susceptible, especially with all of the surrounding infected plants.

Thanks for the help guys. I was inclined to think that the seedling really is mildew-resistant. But, it’s good to hear from the collective wisdom, on the matter.

By the way, it’s been a particularly heavy mildew season here in Maryland. Even some fairly resistant plants are having problems. Some surprise victims are: Rosa laevigata and a local clone of Rosa virginiana. I expected both of these to NOT be troubled.

As far as ‘Carefree Sunshine’ goes for a parent; I haven’t seen a lot of health in the majority of the seedlings I’ve gotten so far from it. And now that I think about it – it is highly possible that the seedling that looks so healthy in that bunch, is from a different pollen parent. I didn’t cover the blooms, just heavily pollinated with ‘Carefree Sunshine’.

Also, I had guessed that the resistance was coming from Rosa carolina – but it’s only just a guess.

Here’s a link where you can see the seed parent.


Looks nice. Ive had mildew this spring and it never mildews here cept for late September before everything goes dormamt. In a way, that is good news. It is helping me cull seedlings. Aint She Sweet x Sunsprite looked like a huge ball of white fuzz haha.

If I remember parts of Carefree Sunshine…it had a lot of HT and mini in it that werent so disease free (Rise n shine, Gold Badge & First Prize out of very foggy memory). But thats for black spot (usually what I memorize for) so I have no clue on mildew resistance.

Personally, I’d just use Baby Love or Rabble Rouser as a pollen parent.

Joan, I have to admit that I have no personal experience with ‘Carefree Sunshine’. However, I do have lots of experience with ‘Baby Love’ and although none with ‘Rabble Rouser’, if my memory serves me right, it is a seedling of ‘Baby Love’, so I would “second” Jadae suggestion!

Jim Sproul

I need to take a comparison pic of Rabble Rouser. It is bred from Baby Love. It is nearly identical in plant shape, formation and habit. The leaves are a bit darker, the blooms are double and the gold is darker. The color is on par with roses like Freedom and Midas Touch (or Henry Fonda in your case Jim!).

So where can you FIND Rabble Rouser? All I can find are wholesale sites. (Did I mention it was on my want list?)

I have a seedling from last year that has proven completely mildew proof. It came from the cross ‘Cardinal Hume’ X (‘Golden Angel’ X R. californica nana) See the link to my HelpMeFind listing below. It is 14 months old from seed and is about 4 X 4 feet and blooms non-stop, tending towards large flushes. It sets seed occasionally with some pollen parents but its pollen is extremely fertile and has set seed on everything I have put it on so far. It has never shown any Mildew whatsoever, even under the most difficult conditions. Curiously, it has inherited the peculiar Cinnamon fragrance of ‘Cardinal Hume’, but is very much like a very densely branching R. californica in growth habit. I have hopes that it will have merit as a breeder.



Rabble Rouser is available at any local retail place that WEEKS sells to.

btw…Rosa californica nana? I must have missed that one in research. Sounds fun.

Paul, very pretty seedling. I love it when a mildew resistant seedling exhibits fragrance! Good luck on using this one.

Jim Sproul

Very pretty little thing, Paul. I like the color contrast of that particular pink and the vivid yellow of the stamens.

I’ll post a photo of the shrub itself. The foliage and growth habit are almost more attractive than the blooms. It is a rose that will look good in the garden even when not in flower; a kind of bluish green and matte, not unlike some Alba foliage.


A comparison of Baby Love and Rabble Rouser for you all. The plant size and habit is near identical. Dont mind the lovely background of the recycling bin lid :slight_smile: lol