HMF usually has a link to the patent. If you get the "Registration name" from HMF, you can then go to www.google.com/patents and type in the Registration name. If it has a patent, it will display the patent information. For example, here is the patent for the rose with Registration name "RADRazz", better known in commerce as "Knock Out".

If you are a premium member of HMF, you can do an advanced search for roses that includes the date of introduction, that could give you a list to review.

Thanks Diane. I guess I will just continue to use HMF. I just found it to be tedious to check for every rose individually. But it is wonderful that they catalog it all in one place. I appreciate the work they do on HMF. I just wish it would clearly show up in "my garden plant list" as either currently under patent or not for each rose... or at least the year that the patent was filed/renewed... or at least the breeder code. That way I could just quickly look down one list instead of looking at each page individually.

Currently some show, but some don't. Oh well.