I looked at the sites that offer roses on fortuniana and didn't find any
rugoses. I think I may email Ken Muncy and ask if he can/will graft one for
me.
Interesting to hear your experience with some of them. I'd like to try a
couple but to be fair I'm not sure Wayside is the best place to get them for a
test run. Not really knocking them, but they aren't know for the quality of
their plants. If I'm testing I'd like to start with a rose from a good vender,
so I'd know if it was the variety or the source.
I had considered ownroot, heavy mulch and shaded feet, but again not sure
that's a fair test of Dr. Manners statement. If I can't find one on
fortuniana, maybe I'll try it that way.

Several sources claim Dr. Huey isn't a bad rootstock for us, in fact most say
it is second best. But when the first choice lasts 20 years and number two is
only good for about 5 there's a big difference. Some of the own roots are
reported to never take off at all. Nematodes don't seem to be that big of a
problem in my area or at least my soil. But then I don't have the typical sand
of most of Florida. Several own roots are at the four year mark and still
going strong. A couple on multiflora are three and show no signs of declining.
Of course none of them are modern roses and none of them have hit the five
year mark yet either.

I bought some hybrid rugosas last year on closeout from
Wayside Gardens. They are grafted, presumably onto
Dr. Huey. The rootstock on the Blanc Double de Coubert
(bush still in a pot until a few days ago) sent up a big
sucker when the warm weather hit and the rugosa leaves
started to show: impatient, I guess.

My experience from a couple hybrid rugosas on Dr. Huey
is that they do okay except in the worst heat here, and I'm
in north Florida in zone 8b. They sulked a bit in the
hottest and wettest parts of the summer here, and had some
black spot problems (presumably a purebred rugosa would
not have those, or would it?).

I wonder how an own-root rugosa would do here with a nice
heavy mulch, if Dr. Manners is right.

I looked at a book on the rack at Lowe's -- might have been
put out by J&P, or maybe by the Southern Living people,
about roses in the South, and it claimed that Dr. Huey is not
a bad rootstock for nematode-infested soils. Huh? (Of course,
J&P would probably write that sort of thing to defend their
use of Dr. Huey.)