Vettin, how wonderful that forum members like you have become so aware of R. multiflora's connection to problems like non-native invasion and RRD! Rosa multiflora can spread in 4 ways: (1) a human sticks a plant (not rootstock) in the ground, (2) an existing multiflora plant tip roots when canes bend and touch the soil, (3) an existing multiflora produces seeds that contact soil and sprout, and (4) a chosen cultivar that has been grafted onto multiflora stock sends up multiflora shoots from the stock and these shoots flower and seed or tip root...or the cultivar reverts completely to rootstock. If your purchased cultivars are properly grafted and well cared for (planted below the bud union, watered, fed, etc.), the plants should not revert to rootstock--whether it is multiflora, Dr. Huey or whatever. If a cultivar is poorly grafted, multiflora suckers may pop up around the cultivar and require removal, sliced away as close to the bud union as possible. As long as your multiflora rootstock remains rootstock, you are not spreading R. multiflora. Pickering grafts its roses on multiflora. I just purchased three OGRs from Pickering. Hope this reply helps! Carol

This post was edited by PortlandMysteryRose on Tue, May 20, 14 at 22:53

Three of my Portland roses from Pickering put out multiflora canes last summer.

Should I replant them deeper, to prevent the same happening this summer?

Nastarana, oh, darn! I'll keep an eye on my Pickerings. I plant deeply so that the grafted cultivar has a shot at producing some of its own roots, thus becoming stronger and a bit hardier. In zone 5, I'd plant deeply.

Nastarana and Vettin, I said "slice" the suckers in my response. Others recommend twisting and pulling off the suckers so the union heals cleanly and is less likely to resprout suckers. I'd be interested in other forum members thoughts on their methods for dealing with suckers.

Carol

Mmm, I have quite a few roses on canina (but not laxa) which sucker. Obviously, being a slacker, I simply sliced the suckers off at ground level....but to my woe, they doubled in vigour, almost overtaking a classic Arthur bell and mangling Jacqueline Humery. Out of interest, I left a sucker on an Iceberg to see the results - in 3 years, the sucker has a woody trunk twice as thick as the main Iceberg cane and will require a good hacking with a reciprocating saw (although I expect I will simply leave it to revert to complete dogrose - it is a handy nest site for a family of wrens). I now do that onerous thing of scraping away all the soil around the crown and graft union and giving the sucker a vicious sideways swipe (it does come away cleanly). I am now debating whether to leave the graft union exposed for easier access as I have no reason to suppose more suckering is unlikely.

Nastarana, another thought: if my Pickerings sucker obnoxiously, I may attempt to root the grafted OGRs and begin again own root. Carol

The reason that multiflora is all over the place is that starting in the 1930's, the US Soil Conservation Service actively encouraged farmers and rural residents to plant multiflora as hedgerows. In fact plants were distributed free of charge by some state conservation departments starting in the 1960's. It was called a living fence. Now hedgerows are excellent environmental features, but multiflora is a nightmare. Birds eat the hips and spread the seeds far and wide. It is seriously invasive. Even without the problem of RRD, it can cause fallow fields to become tangles of barbed nightmare. They are what we in western Pennsylvania called "jagger bushes". You can't get a plow through a field overgrown with multiflora, and it doesn't make good grazing, either.

So I don't think you can take much blame for multiflora. The problem was being created before you (or I) were born.

Note: The link below provides more information, including the horrifying idea that it may someday be possible to eradicate it by RRD.

Here is a link that might be useful: Multiflora Rose

Campanula,
In milder climates, that is a good question, isn't it?--whether to just say "to heck with it" and leave the union exposed...especially when one has battled a number of suckering stocks. I've always planted deeply, hoping that some roots sprouting from a grafted cultivar will help to keep it vigorous when or if stock suckers pop up. (I've grown enough Dr. Huey!) But, oh what a pain it is to hunt down, excavate and hatchet the suckers that surface all around a cherished rose.

Vettin,
Did your question receive the answer you were seeking?

Carol