I know a very hardy peach is "reliance". What is the hardiest of apricot trees for zone 5b-6a? Are the fruits fairly decent for eating, for anyone that has grone them?
My grandparents had 3 or 4 hardy Apricot trees in Northern Ontario (Sundridge/Powassen area) with great success. Not sure what the cultivar was, but the fruits were fantastic. Definitely not like commercial apricots - smaller and a bit drier, but I thought that the flavour was superior to the supermarket ones. So it is possible! A quick web search for "Hardy Apricot" turns up the cutivars 'Manchu,' 'Sungold,' and 'Moongold' AND, there's a chart of hardy varieties grown in upstate NY here along with some information on how they're grown in orchard settings.
Google about "Scout apricot" and "Marden apricot". I have read they are the hardiest but I do not any more have personal knowledge of their performance.
Hardy fruit for zone 5: 'Madison' peach, 'Jerseycot' apricot. They are both supposed to be very good eating, though I haven't grown them, and they may be hardy into zone 4 as well.