Perhaps they aren't budding their own OGR's and their source uses Laxa? Laxa's faults are it tends (like Manetti) to form "carrot root", a large tap root with fewer side roots and it is known for issues when being transplanted. Obviously not sufficient to prevent its use as a stock. I wonder if the gauge of the shank is larger on the Laxa than the multiflora and is better sized to the OGR buds? Perhaps the modern buds are narrower/smaller and the OGR's simply fit better on the Laxa? You might email or call the to inquire. Edit: I just emailed them the question through their web site.

Thank you very much for the expert’s reply. The rose world is full of complexity, and there are always new things to learn, which makes it so fascinating. Looking forward to Rachel’s reply. If laxa tends to produce taproots and is not good for transplantation, it may not be suitable for me since I always move my roses around to create the effect I want.

Back in Pickering Nursery days, I had a discussion about this very subject with Joel Schraven (son of the owner). If I remember correctly, the answer I got was along the lines of: Laxa is better for many of the Gallicanae OGRs in that its easy to get a good bud union matching Gallica-to-Laxa, and that results in a better plant overall.

R. multiflora is great for modern roses and is an easy scion/stock match for HT/modern shrubs, and in Canada it is used instead of "Dr. Phooey" because it seems the Canadian producers know how bad "Dr. Phooey" is for the customer. (Frequently virused, almost always overwhelms the scion by suckering, eventually)

I have just received a lovely response from Ms Rachel Schmitz of Palatine Roses. Prompt, courteous, professional and lovely! It's interesting that Laxa produces a higher crop with OGR's and some moderns.

Hi Kim,

Thanks for taking the time to write your question. We have found that the knits between the old fashioned roses (and a very few modern roses) are stronger on a laxa than on multiflora. What that means in the nursery world we start with 100 grafts and if they don't knit strongly we may only end with 30-50 plants because their union was too weak. If the union/knitting is strong we have very little breakout and will end up with 95 plants.

I hope that helps,

Phone: 905 468 8627 | Fax:905 468 8628

sales@palatineroses.com|https://palatineroses.com
2108 Four Mile Creek Rd.
RR#3 Niagara on the Lake, ON, L0S 1J0

Office Hours: Monday to Friday 9:00 - 3:00

If your conditions are alkaline, Multiflora is a dreadful choice. (Ask me why I know this.)

@jerijen, I have mild-acid sandy soil. Apart from July and August, we usually have loooots of rain here. I think Multiflora is doing well for me, so is the good Doctor, so far. I mostly grow own-root roses and have only a few grafted ones. Time will tell. LOL.

@User, thanks for your sharing. If I consider buying Gallicas from Palatine, I do need to find them permanent space.

@roseseek, thanks so much for your detailed explanation of the characteristics of different rootstocks. It's a precious lesson for me.

One more question. Do you think that Laxa is more drought tolerant since it has carrot root?

Laxa may or may not be more drought tolerant. If there is ground water close enough for the tap root to find and the upper soils are dry, it may be. If there isn't any real ground water to speak of, or it's too deep for that root and any moisture available is distributed through the soil, then I would doubt it would be tolerant. A larger, more fibrous root system will forage and absorb a great deal more resources than a "carrot".

I have alkaline soil (semi arid desert here), and multiflora rootstock works fine here, as does Dr Huey. I prefer grafted roses to own root in my garden. So things work differently in different gardens. Diane

Fascinating information on the differences between Laxa and Multiflora, thanks @User and @roseseek!

One rootstock that I never see mentioned here or by sellers is Indica Major (aka Belmont).

According to several websites it seems to be the most drought tolerant, and also adapted to container gardening. It's downside is that it is severely intolerant of freezes, but for some zones that's not a concern.

Source on this french blog that compares different rootstocks:

http://jardindeluchane.unblog.fr/2018/12/09/rosiers-quel-porte-greffe-choisir/comment-page-1/

Here's a paper that discusses the performance of Indica Major vs Multiflora vs Canina (Laxa):

https://www.ajol.info/index.php/jagst/article/view/31680

It seems to me like trying to find nurseries that graft onto Indica Major might be a good idea for my zone 11 container-only rooftop garden.

But it seems to be a rare choice for nurseries, at least in Europe, so perhaps there are some other downsides to it.

@seasiderooftop, thanks for your sharing. I tried to read french by using google translate. Not very precise but very interesting.

When we first started growing roses at Florida Southern College, I got virus-tested Dr. Huey and Indica Major (a.k.a. Jun Jwan Lo, odorata 22449, and a plethora of other names) from Oregon State University's virus program, to use with our new mosaic heat-therapy program. Soon after, we heat-treated 'Fortuniana' to rid it of rose mosaic (and that remains our source of clean Fortuniana as well as what UC Davis grows). As I recall, the Indica Major was very easy to root and to graft, but the grafted plants were not very vigorous, and didn't flower nearly as heavily as they would on the two other rootstocks. Due to our weird soil and nematode conditions in central Florida, we soon switched to almost exclusive use of Fortuniana. But we found that, even more than Dr. Huey, if you dug up an Indica Major-rooted plant, the roots would produce suckers there for years. It was really hard to get rid of. Under our conditions, plants on multiflora seldom live more than two or three years, so when we've received such roses from Pickering, we always tried to transfer them to Fortuniana as soon as possible. I don't believe we've ever had a rose on Laxa roots.

@malcolm_manners

As we know, Florida is the true exception when it comes to choosing an appropriate rootstock; nothing grows as well in sand/nematodes as Fortuniana! (And thanks for your efforts in generating virus free understock)

I have had experience using Indica Major as a rootstock too, and I can confirm that here in Oregon, its inferior to most anything else. Not terrible, but not as good as "Dr. Phooey" or R. multiflora, although I can't say that I have observed serious suckering from Indica Major here. Maybe its a soil thing?

On the rare occasion that I do bud roses to an understock, I choose Ralph's 'Pink Clouds'. Its ridiculously easy to root and the bark "slips" easily at most any time of the year, unlike multiflora that tends to hold its bark tight except for a few months early in the growing season. I doubt 'Pink Clouds' would be an ideal understock to graft Gallicanae types to (I've never attempted it) for the same reasons nurseries like Palatine and the now defunct Pickering used/use Laxa.