How rootstock affects growth habit

I’ve known that the rootstock will affect the vigor of the plant. What I didn’t know is that it can also affect the growth habit of plant as well.

Four years ago I planted two “Robin Hood” plants in my front yard landscaping. They were upright to about to about 3’or 4’ tall before arching over. We had an unusually dry winter two seasons ago and there was no snow cover during the coldest weather. One of the “Robin Hood” died and the other barely suvived. When this plant came back it’s growth habit changed to a more procumbent plant never reaching more than 18" high and 6’ in spread.

I’m relandscaping the front yard and had to move the “Robin Hood”. When I dug it up I found that the rootstock had died and the "Robin Hood developed it’s own root system. So I’m guessing the rootstock caused the plant to be more upright.

It is something to think about when grafting your seedlings onto rootstock, how will this affect the habit of the plant.


This knowledge at one time was widely known but has subsequently been largely forgotten. Many old references describe the habit of various cultivars as exhibited on certain rootstocks. Some were considered superior as they promoted flowering, were better for certain soils and roses with certain lineages.

I experiment with rootstocks and have found a few I find do well in my climate.

The industry today seems to be moving away from rootstocks altogether but they definitely serve a purpose and they can produce superior plants for the garden if managed correctly. Budding is an excellent tool to use in hybridizing.

There was a paper published in Science 2001 293:287-289 by Kim et al. It was entitled “Developmental Changes Due to Long-Distance Movement of a Homeobox Fusion Transcript in Tomato”. The abstract is below:

"Long-distance movement of RNA through the phloem is known to occur, but the functional importance of these transported RNAs has remained unclear. Grafting experiments with a naturally occurring dominant gain-of-function leaf

mutation in tomato were used to demonstrate long-distance movement of mutant messenger RNA (mRNA) into wild-type scions. The stock-speci

Thanks guys,

I know very little of the various rootstocks used commercially for roses. I do know that there is quite a few different roostocks available for apple trees and wine grapes. Each with it’s own strengths and weeknesses. But I thought they differed more in their vigor, soil preference or disease/insect resistence than in their affect on growth habit. Obviously the rootstock on my Robin Hood was not appropiate for my climate. For now I will leave it as is.

R.canina is used as a rootstock, I don’t have one, but I do have R.glauca which is I suspect is similar. I’ll try budding onto a seedling of that to see how that works and what effect it has on the plant.

When I think of RNA, I think of it as staying within the cell for the production of proteins. I never realized that it can leave the cell and travel to other parts of the plant. It just goes to show how complicated biology can be.


I’m curious to know how they ruled out the possible effect of protein already generated from the mutant RNA within the rootstock tissue being translocated through the phloem and into the scion, thereby producing the same result…

Paul, if you bud onto a seedling you will be forever removing adventitious shoots below the bud union unless you are able to bud below the first seedling node.

Rootstock has to be carefully disbudded to prevent suckering.

I would suggest preparing some cuttings for use as rootstock. It takes some preparation but it prevents years of work in removing shoots of the rootstock variety.

Just my opinion.

Stefan, I believe that they were able to isolate the mutant RNA from the normal scions. Liz

European usual practice for garden roses is budding on seedlings. They do not sucker any more than cuttings. Canina, multiflora, eglanteria, froebeli and many other selections are or were used.

When the seedling is pencil thick it is quite easy to bud low enough to avoid all adventitious shoots.

Known advantage of seedlings rootstock is that they are virus free when cuttings are not so clean.

Greenhouse roses grown for florists are either grafted on cutting grown selected clones, budded on seedlings or grown ownrooted…

Effect of rootstock has been compared for forcing hability, mean stem length and number of harvested stems. Results are quite diverse with i.e. odorata more suitable for winter forcing than is canina. Quite diverse but usually not very consistent as rootstock-scion affinity strongly interfere.

To the point breeding for better rootstocks rarely succeded

So much that a strong tendency for the last decades is going more and more to ownroots that bypass all rootstock and grafting problems.

Thanks for the info guys, I learned something new today.

I have limited experiance with budding, grafting and cuttings. I’ve had the best luck with budding though with the little bit I have done. I’ve never had much luck getting cuttings to root or grafts to take. It’s something that I would like to get better at. I have numerous species and near species plants that sucker quite badly and have thought about getting them onto non-suckering rootstock. It might be easier just to confine them somehow.

Thanks Liz, that does answer my question partly - the other part would be if they found no free mutant-RNA-derived protein in their samples, or could somehow prove that it didn’t originate in the rootstock. Do you have access to the article by any chance?


Stefan, I have a pdf of the article. Send me an email and I’ll send you the pdf. Liz


I have Robin Hood on its own roots, and it is a 3’-4’ arching shrub. Perhaps you have root sport of Robin Hood, as Baby Mermaid is a root sport of Mermaid.


Thanks Jim,

I haven’t seen that dramatic of a change as Baby Mermaid from Mermaid, but it’s certainly possible. More likely, I may have been a little premature in my theory of why the growth habit changed. Last year the plant was getting re-established after the rootstock died. This year was the first that it really came back into its own. Now that the leaves are drying up after my trying to kill it by moving it, I can get a better look at the stems. It seams that the plant wasn’t sending up many new stems, but rather was sending out laterals from the stems it already had. It was the laterals that were spreading out horizontally and not growing upward. I will have to see if it returns to its old self next year.


Baby Mermaid would be fun to use to see if the habit passes along or not. Is it superficial? It would be difficult to know since Mermaid itself is such a picky parent and Baby Mermaid could be so distored that it is even more sterile… or maybe not.

Apparently Austin is using a chromosome doubled form of Mermaid. See:


That would be fun to play with!

I have a Little Mermaid that I treated with nitrous oxide in an attempt to double its chromosomes. It has set several hips. My untreated Little Mermaid has never set a hip. I’ve never seen a hip on Mermaid either.

Congratulations, Jim, for new readers; some background information for the use of nitrous oxide can be found at:


Is there any phenootypic change Jim?

If anyone wants more information, I described what I did in an article in a recent issue of the RHA Newsletter.


There is no phenotypic change.


Did you ever try using nitrous oxide in a pressure cooker to double chromosomes? As I said at the time, I don’t think that the pressure would be high enough in a pressure cooker, but that it would be worth a try.

Here is a link to the beginning of the thread that Henry referred to: