Heritibility of rebloom in californica and palustris?

Having finally stopped procrastinating, I’m preparing to try my hand at breeding some RRV-resistant roses.

My palustris (sourced from RVR) doesn’t look like scandens, it’s not very bright pink, and has single blooms, but it has them all the time, it’s got buds on it even now. RVR rates it as “rrrr.” My californica selection, “New Dawn,” also blooms all the time, and is very fragrant.

While these roses are unlikely to readily accept foreign pollen, and both species have traits that might want a little mitigation (californica suckering, palustris thirst), I was wondering whether anyone here has had success getting extended bloom in their progeny.

It seemed like a good thing to ask about before I considered resorting to Bonica.

Rebloom on palustris is a pretty interesting thing. How long have you been growing it?

I’m totally confused about the ‘californica selection, “New Dawn,”’ and don’t find any such thing either at hmf or Rogue Valley.

There are several selections of R. Californica. Hardy is probably thinking of “First Dawn”.

I’m fairly sure the “repeat” bloom you’re seeing on the Palustris and Californica are climate induced and not actually “repeat”. Californica can flower over a very long season “in the wild” where there is sufficient water and the temperatures remain within the more “spring-like” range. When the water dries up, and/or the summer “heat” arrives, the flowering stops.

Growing Banksiae in Pacific Palisades, about where Sunset Blvd and Pacific Coast Hwy intersect, there are flowers six to eight months in good years. Nigel Hawthorne and Arkansana Peppermint both flowered sporadically from spring through late summer when the real “heat” hits that area. Farther up Sunset, on the eastern edge of “The Village”, O’Neal Blueberries flower and fruit from late spring through late August, sometimes into September. I sold quite a few of them to a client who lived up Chautauqua Blvd. Her four year old daughter was wild for blueberries and she loved being able to say her daughter “foraged” ripe blueberries from the yard all summer into fall. Carol Aguilar, the lady who grew the plant Jim Delahanty and I submitted to Ralph Moore and was determined to be his “extinct” Climbing Yellow Sweetheart, had an apple which flowered and fruited in three flushes a year, every year, like clockwork. Many plants continue performing as if it is “spring”, when they would normally be expected to flower, even fruit, when the conditions remain suitable to trigger the performance. As soon as the conditions change, the performance changes. Milder spring-like conditions which last a long time can easily keep the spring performance going. All of those spring expected events drew to a close annually by August through late September when the sixty degree days gave way to eighty and ninety degree temps. If conditions delayed the arrival of the real “heat”, the plants kept doing what they were doing.

1 Like

The palustris basically just arrived, with a couple of buds on it, so it definitely reblooms in Oregon. One opened today, and it smells quite nice! The only palustris I’ve closely inspected was the palustris plena at SJHRG, so I’m no expert at identifying it, but the foliage, habit and blooms look right to me. The only aspects that look a little bit off, are the thorns, which aren’t very hooked, and the stipules, which are not extremely narrow. Having seen the local native varieties, I don’t expect all species to be clear and distinct, I expect most to vary a lot, including blurring into their neighbors in various ways. Some californica reblooms a lot, some a little, some not at all. It’s said to be generally tetraploid, but not always. Some look like hybrids with other locals, but there’s no one plant I could point at and say the pure species should look just like it. It’s not in commerce in the US, but ‘Rosa X mariae graebnerae Ascherson & Graebner’ is said to be a reblooming, naturally occurring palustris x virginiana collected in the wild in the late 1800s, so I’m not sure what to think about this palustris. Considering the poor luck people have had with rebloom when crossing natives with chinensis hybrids, I suspect it could be all native, but… shrug I guess I’ll find out if I cross it with reblooming chinensis. Maybe.

“New Dawn” was a mistake on my part, make that “First Dawn,” from Suncrest. The flowers are on the pale side for a californica, but otherwise it looks pretty normal. Someone from Suncrest did a long drive around the state, taking cuttings of the more interesting strains they found. “First Dawn” is the best rebloomer of the bunch.
A pic at HMF: 'Q & C' Comment / Question Photo

I’m hardly optimistic about the idea of getting palustris to take californica pollen, but was wondering about the general idea of getting rebloomers from a cross like that. IIRC, there’s been mention here of a rugosa x palustris that rebloomed, but that crossing natives with chinensis/juvenile rebloomers always resulted in single blooming offspring. That made me wonder about all-native rebloom, like that palustris x virginiana, and whether people might have tried that sort of thing out before.

‘Rosa X mariae graebnerae Ascherson & Graebner’ is a rebloomer.
Yesterday I noticed that the parentage on HelpMeFind has recently been corrected into R. carolina L. X
R. humilis lucida. This seems to refute the earlier assumption that R. palustris played a role in the parentage of this hybrid. It could be presumed that DNA analysis has revealed the true parentage. I consider such a finding of ancestry research as very valuable for us breeders and am very grateful for it. So I hope more updates will follow.

@Hardy do you have an update on your R. pallustris ventures? I’m really curious what kind of offspring you’ve acquired.