If you drill down on their web site, it might say, or you could always email them and ask -

Jackie

This might be a little late considering the thread is from way back in April. I had the same question and contacted Dewar via email. They responded and told me that Dr. Huey is the primary rootstock they use. I have two Roses purchased from Lowe's that came from Dewar (Olympiad and New Year). They seem to be doing well in containers.

This post was edited by jamesthepeach on Mon, Nov 11, 13 at 23:12

I am happy too have found your post, james. It's been a couple of years since your post but hopefully will help me save my mom's flower.