On Sat, 05 Jul 2003 20:58:44 GMT, Ryan Vandermaas
wrote in rec.gardens.edible:

I purchased two tomato plants last spring that were simply marked
"Dufresne".

I wish I could help you. I also live in Canada Zone 5a and purchased two
Dufresne plants last spring. Mine have also set fruit and I am unable to find
much information about them. Not much help, but perhaps we could share any
information we receive in private?
--
Gardening Zones
Canada Zone 5a
United States Zone 3a
Near Ottawa, Ontario