Dear Rose Whisperer:
I have been looking for a particular rose variety for a long time, and finally found it offered in an on-line catalog of a well known
nursery. However, it is grafted on ‘Fortuniana’ root stock. I am wondering; is it OK to plant it in my Tri-City garden?
Stumped on Roots
Dear Stumped on Roots:
The understock or rootstock of roses for our growing region is important to consider when buying a new rose. In the US and Canada,
there are three prominent rootstocks onto which roses are grafted: ‘Dr. Huey,’ ‘Fortuniana,’ and ‘Multiflora.’ Let me discuss each of
these a bit and help you make up your mind about the rose you are considering buying.
• First, the rootstock of the ‘Fortuniana’ variety is a very vigorous grower. That is one of the primary reasons why it has been
selected as a rootstock for grafting modern roses onto. Its roots spread very widely (more so than the other commercial rootstocks),
and as such are known to be able to assimilate moisture and nutrients very well. Hence, this rootstock will support a very healthy
and floriferous plant when buds are grafted onto it. One of the biggest drawbacks to roses grafted onto this rootstock is that they
are not very cold tolerant because the roots are comparatively shallow and are therefore very winter intolerant. So, with that in
mind, this rootstock is not recommended for our growing region. ‘Fortuniana’ is quite popular in the southern regions of the US
(particularly the Southeast) since their winters are much more mild than ours.
• ‘Dr. Huey’ rootstock is probably the most common rose rootstock commercially used. It supports a strongly vigorous plant, and is
much more winter hardy than ‘Fortuniana,’ in part because its roots tend to penetrate deeper into the soil. Therefore it is more
widely adaptable to different climates. Also, this rootstock grows well in the large commercial rose-growing regions of south central
California. A rose that is budded or grafted onto this rootstock will do well in our region since it is reasonably winter hardy and has
proven its ability to endure our winters. This is the rootstock of choice for our region.
• Another rootstock from the rose ‘Multiflora’ does well in Canada and other colder regions. It is even more winter-hardy than ‘Dr.
Huey.’ It may grow well in our region, but I personally don’t have a lot of experience with it. Roses purchased from some of the
Canadian nurseries that export to the US may be grafted onto this rootstock.
Another option you may want to consider is buying your desired rose from a nursery that propagates it on its “own roots.” Without
going into a lot of detail, this simply means that a commercial nursery has taken cuttings from a mature plant, rooted them and
prepared the new plant for sale. “Own root” roses are becoming more prominent in the industry for all growing regions of the
country. There are some advantages to this type of plant for our region, since there is no bud union (the point where the buds are
grafted onto the understock) that might be damaged or killed during a really harsh winter. If a rose on its own roots freezes to the
ground, it will come back true to the variety. Also, a rose on its own roots, without a grafted area will not produce unwanted suckers
from the rootstock below the graft. These “own root” roses may be more expensive than grafted or budded roses, but the longevity
of an own-root rose is reported to exceed that of budded roses.
Perhaps the final option is to find a rose bush of the desired variety growing locally and root your own cuttings. This will be the
subject of an upcoming article from the Rose Whisperer, so stay tuned…and go out and talk to your roses. They’ll love it, and so will
you.
The Rose Whisperer
AKA Harlow Young (email: threegkids@frontier.com)
Update to the Rose Whisper article on pruning climbing roses, printed March 2011:
The Rose Whisperer learned a lot about pruning climbing roses while researching last month’s article. But what was unexpected was
the amount of winter damage suffered by two mature climbers in his garden. One (a ‘Candy Land’ rose) had to be trimmed all the
way to the crown (base or bud union) because of severe winter kill. The other, climbing ‘Peace,’ survived with about half of the
mature canes from years past being removed, and the remaining canes being seriously trimmed.