The most comprehensive rose trial project ever

Three years ago we launched an ambitious project, a rose trial in Sweden to find the best
roses for our country, and naturally other regions with a similar climate.
Our rose trial project has now come to a close and we have some very interesting results.
We have had 131 different varieties of roses distributed among 120 private gardens, public
rose gardens and commercial growers throughout Sweden from the Arctic circle in the north
to the southernmost tip of the country. The roses are all relatively new in commerce and
some had not even been introduced at the start of the project.

The rose hybridizing companies involved in the trials are:
Tantau, Germany
Kordes, Germany
Poulsen, Denmark
Austin, England
Baileys Nurseries, USA
Joy, Kahila & Kangaspunta, Finland
Primavera Sunflor Roses, France, that represents several breeders in different countries.

In Sweden we have 8 different climate zones as the country is stretching between latitudes
56° and 69°. Only very few rose varieties can be grown in zone 8 as it has an arctic climate.
Our 120 trial gardens have been located in all zones from 1 to 7. The gardeners have grown
roses before which was a requirement for participation in the trials.

Rose varieties which were not expected to be hardy in the coldest zones 6-7 were placed in
zones 1-5 with a few exceptions. Two gardens in each zone received the same rose variety.
In all, some 3 100 plants were distributed. The gardeners had to evaluate the roses’
performance according to a standardized evaluation form that was equal for all gardeners.
Once a year the trialists were expected to electronically feed data concerning the roses into
the data base of Sveplant, Sweden’s largest data base of cultivated plants. A special program
was developed to process the data for each rose variety concerning growth habit, disease
resistance, flowering period and abundance, winter hardiness and many other parameters.

By the end of 2014 all data had been collected and a group of 3 rose experts analyzed each
rose variety giving them a rating from very good to poor, recommending good varieties for
Swedish conditions. Generally speaking a majority of the roses have shown to be healthy and
floriferous in comparison to older varieties and some of the results have been surprising
regarding hardiness.

The Finnish roses need another year to develop well as they were small rooted cuttings on
arrival.
Thus far they have shown to be extremely hardy and healthy.

We want to emphasize that the results of the trials are only indicative, given the relatively
short time the roses have been tried. In order to safely assess a rose’s hardiness, a period of
at least 8-10 years is required.

We divide the roses into three categories. The first being roses we can recommend
for cultivation in our country because of health, hardiness and abundance of flowers. The
second category is roses which are good though with some reservations due to sensitivity to
diseases or flowers sensitive to rain. The last group is the roses we cannot recommend, at
least not for outdoor cultivation in our climate.

To see the individual results, please click the name of the rose.