open pollinated seeds of 3K20 available

Hi! 3K20 is a very fertile tetraploid op of ‘Max Graf’. Looking at the larger semidouble blooms and plant habit it is likely a cross with ‘John Davis’ next door. It makes very large hips and is very very healthy. It doesn’t defoliate from spot antracnose like L83 does (they are planted near each other even and ‘Max Graf’ is resistant it seems to a large extent too). 3K20 makes very heafty long somewhat flexible interesting brown canes. It may be nice to breed climbers from. There is a slight rugosa influence in the canes because of the thick growth and brown color even though it is not more thorny or otherwise show strong rugosa tendencies. It is a spring blooming soft, nice pink with relatively large blooms. I have gotten repeat blooming seedings from it before. I hope to use it in crosses more in the future. It is very hardy, hardier than ‘Max Graf’.

Please email your name and shipping address if you would like some seeds of it and I’ll get them sent off.


David ; I would be interested in a few available seeds of variety OP3K20. Thank you

Milford Clausen

420 Pine St.

Waterman , Il 60556-9774.

thanks for the seeds David, they showed up in the mail today. I’ll let you know what comes from them.

You’re very welcome. I’ll be excited to hear in the years ahead.

Hi David.

Assuming they are self-pollinated vareites, are the resulting (3K20 x OP) seedlings expected to be as good as using the original 3K20 in terms of passing on the desirable traits in breeding?

That’s a great question George. It definately can be true. A person just has to test the op/selfed offspring and see and it depends on what the complement is in the genetic contribution of the other parent used. I suspect many of the seeds are likely selfs. Inbreeding in roses is something most of us typically don’t investigate to the extent we could. In past articles and posts I described the great progress in mums for parent building Dr. Peter Ascher did (outcrossing hexaploid) and filtering out undesirable alleles via inbreeding and then having overall better quality offspring for the traits selected for when selected inbreds were used. Of course inbreeding can produce plants with less vigor, etc., but we are interested in their offspring more than them. If we choose inbreds with relatively more vigor, we are hopefully selecting individuals that have less deleterious alleles. Of course, having heterozygosity at genes can help, but we can restore that later in our outcrosses. Roses like ‘Dorcas’ for instance give consistently heafty relatively uniformly vigorous offspring and I think it likely has limited “genetic load” and we can use inbreeding to help us develop parents that also are like that. Disease resistance and other traits besides heafty, relatively strong offspring need to be put in the mix so perhaps crossing ‘Dorcas’ and ‘Knock Out’ would be an interesting mix to likely provide a population of relatively vigorous offspring from which to select from. Other traits can be worked with besides overall vigor. Dr. Ascher built parent lines that produced consistently colored offspring for instance.


The first two of these seeds came up the other day.

I have between 5 and 10, have not looked closely lately and counted them since they germinated at different times and are in different batches. I also have 2 of my 3 max graf X My Stars seeds which germinated and are doing ok so far. Can’t wait to see both of these crosses grow up. Thanks David for the seeds and also for the mental seed planted in my head about max graf being fertile which allowed me to do this cross.


You’re welcome Patrick! I first got ‘Max Graf’ years ago because I wanted to study the frequency of unreduced gametes in roses. As I looked through Modern Roses saw MG as well as ‘Robin Hood’ could produce tetraploid offspring as females and got them. My hope was to raise seedlings from crosses to males of different ploidies and then count the offspring and see the ratio of unreduced eggs.

I never really did that as fully as I hoped to, but did get some tetraploid offspring of both. I’m excited about your Max Graf x My Stars cross!!!

I love L83 and the Explorer roses that trace back to Max Graf and again with MG through Rosa x kordesii, but many sure get leaf spot (likely Cercospora) bad here. With MG and 3K20 being resistant to that leaf spot as well as black spot, I think there is great potential to start new lines from MG that get around that problem and also incorporate different germplasm with MG to get different types of hybrids. MG acts as a nice bridge between diploid and tetraploid roses capable of crossing with both and producing offspring of variable ploidy levels.

Thanks for the update and good news about your seedlings,