What makes red?

I’d like to open a discussion for non-scientific folks like myself to talk about color and color inheritance in roses. I haven’t studied pigments and the like, so I’d welcome all levels of input, questions, and discussion about color and color inheritance.

I’ve never focused on breeding for red.

For me, a desirable red rose is one that doesn’t have pink in it. In the industry they call roses “red” that have a strong element of pink in my opinion and I always feel a little taken. For instance, Cuthbert Grant and Double Knock Out are two roses that have been called red that you have to look at sideways on a Wednesday morning to see as red. Cherry Frost, Kashmir, Mr. Lincoln, and Canadian Shield are some roses that I see as being true red.

When we were in elementary school we were taught that red and white make pink. We mixed up the paint and it happened. But that’s not what’s going on in roses, right? There is some element of blue that makes red into “rose” or dark pink. It’s not just adding white.

Red remains a bit of a mystery for me. It is so so easy to turn a red rose pink in the breeding process. So can I even use pink roses at all? I’m not after another fake red like Cuthbert Grant. Do I cross Cherry Frost with my orange-yellow roses? I have this feeling that if I crossed Cherry Frost with High Voltage all the seedlings would be f****** pink.

By the way, what color is Highwire Flyer?

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This might help:

Inheritance of Magenta Red Color in Roses
Dr. Walter E. Lammerts
American Rose Annual 1960



The patent says “deep pink”, and that looks about right to me.

I understand your frustration, and its a complex question. Answering it with what I want to say would probably not help.

The short is: A lot of things make a red rose… red. I think the first thing to accept that there are many chemical sources that create red. Categorically, we could call them blue-red, pink-red, orange-red, and wine-red. There are actually more. ‘Frensham’ was found to have a unique wine red chemical. In most “true reds”, such as ‘Ingrid Bergman’, all of these are likely present, but blue-red and the rare pigments we’re not going to confuse this post with are far less found. It is easiest to think of these categories of red as additive combinations than one specific category.

The second thing to accept is that some reds are not self reds. Double Knock Out is not a self red. It is a bicolor. The petal reverse is substantially lighter than the petal face. This means that the roses primary color is its reverse. However, at opening this is not apparent and they can appear quite red. This illusion soon fades to the reality of a light red w/ a lighter reverse. In breeding with roses like this, the reverse tone can be more common in the seedling colors. Knock Out is a self color, and Meilland tends to use it over DKO when breeding darker colored roses. On 6 known releases, in fact.

The third thing to consider is that A LOT of things work against red in a similar way that a lot of things work against yellow. The first is yellow itself. The second is the suppression “white”. Last, like yellows, degradation can assist in either altering the red or lessening it. The presence larger doses of “orange-red” can help reduce this, but it comes with the risk of poor petal drop.

‘Black Cherry’ is a decent example of using pink roses and white reverse roses with red roses to get a very saturated true, dark red. However, it required using a rose very saturated in orange-red and pink-red…twice. There are pink roses that will throw red much more readily but they’re somewhat of a surprise to find. Some species matches will do this. Some things are buried in the gene expression, obviously.

So my advice is take take a few blooms at different stages during July (May blooms don’t show much degradation), and looking at the petal face and reverse very closely, before considering what might be good matches.

I tried to make this as linear as possible.


Once I got a nice red out of “Olympiad” OP. It was neighbors with “Mr. Lincoln,” at a local park that has a big rose garden, so that’s just a guess. Good luck to you!

One popular red rose, Lasting Love , was bred from an orange and a pink.
I don’t grow Lasting Love, but saw the climbing version at Bagatelle in 2022, and to my eyes it was a very nice red. In some HMF pics, it does appear to lean slightly cooler though.

Also, I believe the famous chart below mainly applies to diploids, but it may still be helpful (apologies, because I never knew who actually made the original chart, so can’t give proper attribution):

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Many thanks, pacificjade, for this thoughtful response.

My brain just doesn’t want to slow down enough to properly digest the knowledge you are imparting. As a nursery/greenhouse owner in the spring I have this constant feeling of being frantic and overwhelmed that creates mental turbulence.

If you are ever in the area of Fargo, ND, in July or August, please get ahold of me and stop by. I would love to pick your brain about color inheritance as we walk around and look at my seedlings.

If I get serious about breeding reds, I will revisit this and try to digest more.

Your reference to a “suppresion white” is also very interesting, as I’ve wondered about whether white is an absence of other colors or a dominant suppresion gene.

Some of my most red seedlings this spring are coming from a pure white mother.

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If you look at King J and Ensio, both hybrids of Rosa rugosa alba, you can see how polarized the expression of repression genetics can be.

I am working with a lot of colors and this year a lot seedlings do not look like their parents. I assume they are labeled right, but is it maybe the DNA of the parenthistory which effects every crossing differendly? Like there are a lot “real” red roses with a lot differend parents…how much do you people look at the parents history to maybe walk around the stats given above? For now I do not do any research what to cross…I just have a main goal and use the flowers and pollen I have available each single day.