non rose plant from Zlesak

See:

and

It’s a beautiful plant. David graciously sent me a small one. Unfortunately it didn’t like my climate.

Thank you Henry :0). I really like this ninebark seedling because it reblooms with flowers at the terminals midsummer and on and that forces branching from beneath and nice warmly colored shoot tips without pruning. Consistent and strong rebloom in ninebark is not something I’ve seen in other cultivars. A colleague is working on documenting gene expression of the terminal flowering locus (TFL) gene in this cultivar and seedlings of it versus the standard ninebarks and seedlings of it that do not rebloom to see if a mutation in this gene may be linked to rebloom- kind of like a disruption of the key/primary gene in roses that is generally the major gene that leads to rebloom. I’m having fun helping with the project and look forward to what she learns. Years back I tried crosses of ninebark with its close relative Japanese spirea/Bumuld spirea, a species that blooms on new wood/blooms first year from seed. I assumed none of the crosses took. Perhaps I’m wrong and the source of the rebloom actually is spirea versus a mutation in solely ninebark??

How neat, David! That would be exciting!

The colorful ninebark is very attractive and two plants did well for me in pots this past summer, courtesy of David Z. But one thing puzzles me. The plants arrived with the remnants of early spring bloom despite their height of under 1 ft. They grew and grew many shoots to perhaps 2 ft by frost time in mid-Oct. But there was not a sign of another flower on either plant. Could there be a latitude or temperature effect going on here? Or might it be simply lack of maturity of the plant. Seeing that it had thrown a few flowers early, I doubt that last explanation.

We’ll wait to see next year, but I wonder how widely this has been tested in more southerly climates for rebloom. I know that older CVs of ninebarks do well here. A neighbor had a big one for years that bloomed profusely early in the season.

http://plantsnouveau.com/plant/physocarpus-opulifolius-sweet-cherry-tea/

That is really interesting Larry and a great question. I think the plants I sent you were cuttings from late 2018 that I grew in the greenhouse through the winter and likely confused some before sending them to you come spring. It’ll be great to learn what they’ll do this coming season for you in regard to rebloom. Maybe daylength plays a role too?

If a mutation in FLC is the cause of blooming on new wood, it generally doesn’t depend much on either daylength or vernalization, in the Rosaceae. Of course there are roses that vary a lot in their reblooming propensities. I notice that no matter what I do, in terms of water, fertilizer and location, Soeur Therese blooms very early in spring and again in fall, but rarely through the summer. ON the other hand my Ruby Slippers blooms continually, not in flushes when in a pot right next to it. Even though it is “continuous bloom” it is nowhere near the total flowers of rainbow KO which is the presumed parent of RS. Rugosas of course are a bit different from any of the above in deciding when to be repeaters.

Fall raspberries go on until they get frozen putting out multiple laterals and new canes.

I have the ninebark (Rosaceae, but further away from rose) out there somewhere with all the other pots set down in the ground and covered with leaves. I’ll uncover them in early March. So it will have cold season, and short days and I’ll move them to a bigger pot and see what happens. The way things are going, we may not see below 20 F until at least mid-January (or perhaps all winter). Maybe there is a critical biomass effect for rebloom?

That’s a great point about a critical biomass maybe being important for rebloom for them Larry. They were little plants when I sent yours in 4" pots. Some seedlings of Sweet Cherry Tea bloomed the first year, but only when I pushed them with starting them early (germinated January I think) and got a good amount of growth on them the first year with lots of pot upshifts. The first year blooming seedlings looked proportional in a 3 gallon pot by their first fall.

If the reblooming trait came from Japanese spirea, that would be quite botanically interesting as an example of trait introgression via an intergeneric hybrid.

On the other hand if it was a mutation purely in ninebark as sounds likely, that may make the plant even more appealing in the native plant market. Early in my career I worked some years in environmental education, and at the time our on-site native plant nursery (used for conservation projects, not sale) included quite a bit of ninebark (at the request of a colleague, as I recall). We were only using the wild-type, but my understanding is that ninebark cultivars are popular plants in the native plant trade.

If your colleague’s work determines which was the source of the trait, it would be interesting to hear.

It may be of some interest that the maternal parent of ‘Sweet Cherry Pie’ was also itself a named release by David. Congratulations on the success of this multiple-plant-generation project.