Another new hybridizer has a million questions

Hello rose fanatics!

I’m just starting to get involved with hybridizing (haven’t actually tried it yet), and have a few really basic questions you might help me with.

First of all, I am very interested in creating new breeds of moss roses, so if anyone has any useful suggestions in that category, I’d greatly appreciate it!

Also, I need some info on dominant and recessive colors in roses. If I were to cross an orange blend with, say…a red rose, would the red usually dominate?

Another thing I was a little confused about when I read the beginner’s manual was the part about certain roses not being compatible parents. Could I cross something like Joseph’s coat with an old garden rose like Red Moss?

Obviously I have A LOT to learn about hybridizing, but I am a devoted and passionate rosarian and someday I hope to be posting pictures of MY new creations on this site!

Hi Kate!

In the Winter 2002 issue of the newsletter there are some articles related to inheritance of colors in roses that you might find interesting. Past newsletters are available for sale and are filled with lots of interesting articles. When I first started I treasured buying back issues and learning as much as I could from others. Also contacting individual authors and asking them questions regarding topics in their articles was very helpful too and was the starting point for some good friendships.

I love moss roses too. I had Salet and some other old garden mosses, but have made the most progress with Ralph Moore’s ‘Scarlet Moss’, a mini. Mr. Moore has done a lot of breeding work to bring this trait into repeat flowering modern roses and if you are willing to use his hybrids you can save some time. I’ve grown a few of his other moss minis, but only used ‘Scarlet Moss’ so far. You can get some full sized roses when crossing minis and full sized roses.



Color inheritance is very messy in such complex hybrids as modern roses – basically all you can count on is getting a pink from nearly every cross you make!

The question regarding incompatibility between different groups of roses I think probably arrises from the problem of polyploidy – there are other barriers to hybridizations between different roses, but it is probably the biggest. To put it simply (Ha. I’ll try) different groups of roses have different numbers of chromosomes The main two groups are the tetraploids (28 chromosomes) and the diploids (14 chromosomes) Basically, a hybrid between a tetraploid and another tetraploid will usually work smoothly, and a hybrid between two diploids will usually work smoothly. There are LOTS and LOTS of exceptions to that, and it gets very much more complex, but I’ll leave it at that unless you want more detail.

The tetraploids include all hybrid teas, floribundas, grandifloras, miniature roses, almost all of the old rose classes – gallicas, albas, bourbons, and yes, mosses, to name a few. Joseph’s Coat is also a tetraploid as are many modern climbers.

Diploids include the rugosa roses, teas, chinas, ployanthas, and a large majority of the species roses.

That is a very incomplete list (and a lot of generalization) but it should serve to give you a general idea. If you want more specifics, look at the links section of this web page – there are some very helpful pages there. And if you are just utterly confused, don’t worry about it too much – unless you grow a lot of rugosas, it is very likely that basically all the roses you grow are tetraploid, and should cross-breed with no problem.


I second David’s comments: you will save 20 years work by working with a rose like Scarlet Moss. This is a superior breeder and its offspring are fully remontant when crossed with another remontant.


Another suggestion might be to purchase the two very excellent handbooks that RHA has in production…“Hybridizing Roses for Beginners” and the “Rose Hybridizing - The Next Step”.

Both are available. You can download prices and addresses from this website.

Lots of answers to all your questions!