It depends upon which trial. Some have been in existence for a very long time, others are relative new comers. You had the AARS trial gardens for decades; there are the European trials at large, public gardens; American Earth Kind Trials; one at Rose Hills Cemetery here in California and a newer one back east among others. They're where roses are grown in a garden, some sprayed, some not; the level of culture varying greatly from trial to trial, and evaluated for specified periods of time. How valid the results should be considered for you and your area depends upon where they're held, how close to your conditions and climate those where the trial is held are, what the stated criteria are for the trial and how knowledgeable their judges are. It's fun and interesting seeing a rose has won something, but it all depends upon WHY and WHAT it won. Googling the name of the trial and researching who and how they determine winners can be rather "illustrative". They're going to vary from honestly valid trials all the way to the rose version of a reality show competition. Kim

..."illustrative..." very interesting to me

I was just curious because of the word "Trials". It evokes an image of war trials or tribune. Something about the term sounds harsh to me when referring to roses.