In Zone 3 garden centres, one of the most common questions is: Do you have a yellow Climbing rose? Customers are very disappointed when the answer is that none have been developed. How then to develop such a rose (assuming that Agriculture Canada breeding programs don’t have any in the works).
First, it should be established that the most valuable staminate parent to use is ‘Hazeldean’ (Rosa spinosissima altaica x ‘Harison’s Yellow’). It is the hardiest yellow shrub rose in existence and it will repeat its bloom in late summer. Indeed, the Morden Research Station has tall yellow selections with ‘Hazeldean’ in the parentage. And Peter Harris developed a tall, yellow selection by crossing ‘Golden Showers’ with ‘Hazeldean’. R 15 lacks hardiness for Zone 3.
The obvious next step is to cross Rosa laxa with ‘Hazeldean’ hybrids and develop suitable breeding lines. While Rosa laxa has only single, white flowers they do repeat and the tall (3 metres) shrub is hardy to Zone 2. For developing another breeding line to cross with Rosa laxa/‘Hazeldean’ hybrids, I would suggest that Rosa laxa be crossed with the Rosa spinosissima hybrid ‘Maigold’ (a small Climber), since this would likely add vigour and fragrance to the progeny. It might also be valuable to cross Rosa laxa with the superb small, yellow Climber ‘Lichtkonigen Lucia’.
The hardiest Climber is the Finnish developed ‘Polstjarnen’, a Rosa beggeriana hybrid developed in 1937. This cultivar is hardy to Zone 2. I speculate that it is a hybrid with Rosa multiflora. If so that would mean that it is a diploid. While the flowers do not appear to have much fertility (I never see hips that have been open or self-pollinated), I crossed a few flowers with Rosa acicularis. Lo and behold - hips formed! If the seeds germinate, it means that ‘Polstjarnen’ has a lot of possibilities to develop very hardy Climbers, including the much sought yellow colour by rose enthusiasts living in very cold climates.
I am trying for something a little less hardy (at least hardy to zone 5). My starting point was Peter Harris’ R-15. I crossed it to Rugelda ( http://home.neo.rr.com/kuska/RugeldaXR-15%20seedling.htm ). Rugelda is supposed to have rugosa genes. I have kept 2 seedlings, the one in the picture (#228) has the better flower and does not get blackspot. The other (#229) has a poorer flower and gets blackspot but not to the extent of shedding all of its leaves. Neither reblooms. None of the pollinations on # 228 set hips. Only one of the pollinations on # 229 has developed into a hip (pollen from an open pollinated seedling of Bayse’s amphidiploid (R. Abyssinica X R. Rugosa)). I do not yet know how many hips I have from #228 and #229 pollen as I do not keep a record when I pollinate. I record the sucessful crosses when I harvest the hips. I think that there are some.
I have some other seedlings that are supposed to have R-15 as a parent but they do not have yellow flowers.
Does anyone know the hardiness rating for 'Golden Glow’and ‘Goldbusch’? Obviously they aren’t in the league of the heretofore mentioned varieties in terms of hardiness but mightn’t they be valuable resource for breeding cold hardy yellows, say, crossed with ‘Hazeldean’? Thanks, Robert
Correction to the automatic link on my last message: http://home.neo.rr.com/kuska/RugeldaXR-15%20seedling.htm
For some reason the site will not accept the full address on the “Page link” line. You will have to use your browser’s copy and paste function.
Further information re. the hardiness of R15–
It has been grown at the Morden station for at least 3 years, and has survived but has not flourished there. It is apparently hardy down to somewhere in the -20 to -25 F range, but below that temperature it freezes back. Each year it puts out new growth from below the snow line and consequently does not make much of a display because it blooms only on new growth from the previous year’s wood. Still, I have hope that it may be useful in developing a hardy, repeat-blooming climber or shrub. Anyone who wants wood of R15 may have it by asking.
I have a few hybrids from a Ross Rambler seedling x R15, but have seen only one of these in bloom (it apparently got its color from Charlotte Armstrong or somewhere farther up the line). Perhaps next spring will bring flowers on the others (they are nearly 3 years old). I do have some repeat blooming seedlings from R15 pollen on HTs, floribundas, and minis, but I do not know how hardy they are.
My idea of a plan would be to work with Hazeldean and heavily inbreed it with 2 or 3 other studs. First I would try to inbreed Hazeldean (am I right that its very fertile, or am I dead wrong?) For 2 or 3 generations. In that way we can carefully select and eliminate certain “tender” genes. Then I would inbreed R-15 by itself and carefully eliminate certain genes but maintain the yellow and climbing trait. And I would also cross laxa with Hazeldean, and then inbreed those seedlings a few generations for the color yellow and cold hardiness. So we’ll end up with 3 plants heavily inbreed with Hazeldean. With those plants I would cross and inbreed, outbreed, with one another, hoping for the best.
Thanks for mentioning ‘Goldbusch’ and ‘Golden Glow’. I expect that ‘Goldbusch’ would be hardy to Zone 5. ‘Golden Glow’ (Climber), of course, is in the parentage of ‘Goldbusch’ and has Rosa wichuriana in its pedigree. I know that ‘Goldbusch’ is very fertile as a pistillate parent, and probably hasn’t been used enough in breeding programs. Interestingly, Dr. Buck’s ‘Applejack’ (his “antifreeze” for use in breeding programs) has ‘Goldbusch’ and another yellow (‘Joanna Hill’) in the pedigree plus Rosa laxa. So ‘Applejack’ would also be good to use in a breeding program to develop hardy yellow Climbers.
Henry, I really like your RugeldaXR-15 seedling. Very nice yellow!
I’ve always been fond of ‘Rugelda’. I know Moore was using it for awhile but I can remember what came of it? I know it had a good dose of rugosa in it. As I’m trying to breed evergreen roses it isn’t one I’d consider using but great potential there. Sounds like a wonderful cross.
Peter I think your R-15 is really lovely. How is the repeat? I would mind working with it and ‘Hazeldean’ a bit myself. I saw ‘Ross Rambler’ over at Kim’s. It certainly is fascinating as well.
I got ‘Goldbusch’ on a lark a couple of seasons ago. I can say that it flushes well in the low desert for Spring bloom without very much chill. Moore has used ‘Golden Glow’ extensively of course and with much success. Thanks, Robert
Another hardy, repeat blooming yellow spinosissima hybrid that may be worth using more is Von Scharnhorst. Jerry Olsen recommended it to me. It is hardy to the tip in his yard and had blooms on it a couple weeks ago again (zone 4). It is a little shy in repeat and gets blackspot, but is about 7-8 feet tall. It’s a parent of J.P. Connell. Jerry Olsen gave me pollen of Von S. last year and I have one wonderful blackspot resistant low growing light yellow shrub in the seedling beds. I’m trying to root some cuttings of Von S. now and will hopefully have some to share for those that want to give it a try.
I’ve not been impressed with Goldbusch. It will kill back some in harsh zone 6 winters. OP seedlings tend to be weak and bloom in very pale pastels. I did use it in a few crosses, but didn’t keep any seedlings. I don’t remember why.
A rose I got to try breeding with is Mr. Nash. This is a found climber which blooms apricot/yellow and has given some yellow seedlings. It is supposed to be zone 5 hardy. I got mine from High Country Roses.
Next year I hope to cross Ross Rambler with several yellows and see what happens.
R15 is not a repeater, but in a good year it will almost seem to be. Since it blooms on new growth from the previous year’s canes, it will generally have an early group of blossoms along the canes (these often come early in May or late in April here in Charleston, WV, but always appeared on or slightly before April 15 in Lubbock, TX). The early blossoms are followed by a scattering of blossoms toward the end of June. If the winter has been mild, the first flush of blooms is scattered out more and almost runs into the late blooms. The late blooms are just from side shoots that grow longer and take longer to make the buds, or just start growth later. They generally appear in terminal clusters.
For those who are wondering, R15 is very fertile as a seed parent–but the seeds almost don’t germinate, and if they do, the resulting plants don’t grow. It’s much better as a pollen parent, producing lots of good pollen.
BTW, if anyone has Hazeldean, I’m looking for pollen to use next year. I’d trade Ross Rambler pollen (next spring), a Ross Rambler sucker now, unrooted cuttings or seed from a probable tetraploid rugosa, or?
This is really interesting. I started looking at some of the roses mentioned here. I came across Dr. Frank L. Skinner. He has produced some very interesting roses using R. spinosissima and R. Laxa. Suzanne is his. I wonder how is other roses are. Haidee is of the same cross as Suzanne. Has anyone worked with this rose? Does it set hips? Are any of his other roses good parents? How would some of his work fit in with the goal of a cold hardy yellow climber?
Doesnt look like much of his stuff is easily available though.
I have a question about R. Laxa. What is the differenct between R. laxa and R. laxa (Retzius)?
How is Harrisons Yellow for a parent. It it something I should consider? There are so many possibilities to try I am starting to wonder where I should start with my hybridizing. I still plan on working with Applejack and Suzanne.
The rose called “laxa” is reportedly a hybrid of R. canina and is often used as an understock. It is not as hardy as R. laxa, Retzius.
Rose laxa, Retzius is a tetraploid species from central Siberia. It is extremely hardy and disease-resistant. As far as I know it is not used frequently as a rootstock for roses. It grows 6-10 feet tall, and has relatively sparse blossoms, usually white and about 3" diam. It has been used in breeding by several Canadians (Percy Wright, FL Skinner, and others) and by Griffith Buck.
‘Haidee’ is more fertile than ‘Suzanne’ as a pistillate parent but the flowers are not as double. Interestingly, while “alley surfing” for fruits yesterday I discovered a large patch of ‘Haidee’ growing at the back of a property. The owner of the house said it had been growing there for at least 36 years. I have developed one selection from op ‘Haidee’ that is lavender in colour and named ‘Arctic Nights’. The shrub never wanted to size up for me but apparently is doing well at the Montreal Botanical Gardens.
I have Hazeldean and should it survive my anticipated move to a new home I would be happy to send you pollen next season.
One more option. ‘Ames Climber’ (Rosa blanda x R. multiflora) with small white flowers can easily reach 2 metres, and while only once blooming it is very floriferous. If it was used as a pistillate parent and crossed with a tall selection of Rosa acicularis, it would produce tetraploid progeny. A (Rosa blanda x R. multiflora) x R. acicularis tetraploid breeding line would be hardier than ‘Ames Climber’, and potentially it could be quite floriferous. This breeding line could then be used to cross with yellow Climbers. The first generation would only be once blooming, but F2 sibling crosses should maintain the hardiness of the F1 and much of the progeny would have repeat bloom. The two advantages of developing this breeding line are: 1. Rosa acicularis can add extreme cold hardiness. 2. Rosa multiflora is unsurpassed in increasing floriferousness. What a great combination!
Would it be possible to mix yellow climbing minis with hardy briars to get the wanted result of more warm-toned hardy climbers? I was looking at Laura Ford and Warm Welcome again, and it reminded me of this thread.