Hi Folks,

Has anyone hybridized with Knockout?

If you wish to share the info, what kind of roses did it produce. Any interesting common traits?



I used it extensively for the first time this year, so I won’t know for a few months as to how the seedlings turn out. However, I will tell you that it is not a good seed parent (very few seeds and poor germination). It is not a great producer of pollen either, but the pollen seems to be accepted on most roses. If you want to use it extensively as a pollen parent, you will need several plants. I have 13 of them, and I still had a hard time getting enough pollen.

It seems okay. I like the fact that Razzle Dazzle is in the parentage. It might be interesting to breed back to a bi-colored floribunda to combine health with a better color pallette (Knockout as a flower is very bland). Im looking forward to seeing Double Knockout in the future and how it compares. The pictures make it look more interesting. So far I think that Blushing Knockout looks the best due to the more “landscape-friendly” color. Anyone want to take guesses if the color sport transfers or not?

This article is interesting about how Knockout was developed.


I’m excited for Double Knockout. It is a full sib seedling of Knockout and not a sport. Bill Radler said it has greater winter hardiness than Knockout. I love the Blushing Knockout too and think the color is very pleasant. I saw it first last summer in a display garden and was very impressed with it. At first I didn’t know what this great landscape rose was and searched and searched to try to find a tag around a cane and finally learned its identity. The pink Knockout, although different, just doesn’t seem to have as much character. Maybe because so many other roses are a medium pink.


Yeah I went looking for Double KO (hehe love that abbreviation… the breeder needs a Total Knock Out rose…) but I guess thier press release was a wee bit early by Star Roses so we have to wait a year+ or so.

Sorry, the above link is:

Tom Carruth of Weeks roses produced a new rose from ‘Knock Out’ for 2006 named ‘Home Run’, that I am sure will be a winner and should be an excellent candidate to use for breeding purposes.

Jim Sproul

I planted Knockout in a whisky tub. After two years it was moved and new plants put in. I recently noticed several rose plants had srouted up arround the site of the tub. I don’t know if they are seedlings or rootstock but will watch to see!

Hmmm, I’m pretty sure I saw it (double KO) at a garden center near my home last growing season. Assumed it was a sport (as there’s already 2 of the original), and knowing the original KO wasn’t a great breeder (which I already have), passed it by. It is attractive.

Chris Mauchline

Chris, Double Knockout according to Bill Radler is not a sport, but a full sib of Knockout. That’s great you saw Double Knockout for sale. I hope there’ll be some for sale near me next season. I’m hoping to get one and confirm its ploidy along with Home Run (thanks for the heads up Jim). Hopefully they’ll be tetraploid (Knock Out is triploid) and be more efficient than Knockout itself to transfer disease resistance genes into other new roses.


Digging up the past a bit here…

As a bit of a follow on from this has anyone grown any of the ‘Knock Out’ roses or ‘Double Knock Out’ as own root roses? If so how do they do?

Also David, did you ever confirm its ploidy? Is it triploid like ‘Knock Out’?

Hi Simon,

The Knock Out roses are generally grown as own root and do very well.

Jim Sproul

I’ve only ever seen our ones grafted onto Dr Phooey :frowning: That’s why I asked as the Dr is hopeless here and I’d want to convert it to an own root plant.

Most Knock Out roses grown worldwide are on their own roots. Double KO is indeed a sister seedling of the Original Knock Out, Bill Radler made the same cross the following year.

Hi Simon, In a recent HortScience article we confirmed Double Knock Out, Sunny Knock Out, and Rainbow Knock Out are triploids.

Double KO was fully fertile for me as a pollen parent. Its definitely 300% more aesthetic than the original – that is for sure. The red is one tone darker (almost red LOL) and the farm more double buds look nice. They pop open fine for a landscape type, and make a decent display. The pink sport is undoubtedly ugly as sin. Its vomit pink, lol. I was once scolded for calling Barbara Bush “old lady pink” when I was a teenager though, so there is no accounting for my descriptions :stuck_out_tongue:

Oh yeah, the extra layer of petals passed on. I received zero singles, but I used a very double female parent, which also has double parents.

Hmm,very similar situation here Simon. When I bought KO eleven years ago it came from J&P grafted. At the time I don’t think they offered any own root roses. I planted the bud union below soil level in the hopes that it would develop its own roots. For the most part I think it worked except there is a deformity of growth of what was once the bud union.

As you can see I’m not a big pruner. I didn’t site it very well and it has lots of shade causing neighbors that grew very tall in those years. It has partially overcome that by growing very tall (It’s quite a few feet taller than me). I came to the conclusion a few years ago that it could get shaded to death. I struck a few cuttings from mine in the chance that my original should die. My experience is that it roots very easily- but not all cuttings are the same. At least some will not be tall or have any vigor and others will be great (I say that but I stopped after I got my one good one- honest). Perhaps this is a rose to where it matters from where you take the clipping.