In earthtainers? I could buy a couple good sized (12") transplant, or use up some little ones I have left over: (six inch)
Probably this weekend (Zone 5) Ottawa.
Just a thought....
If you have a South facing exposure, and can shield the EarthTainers from the North winds, then you will have plenty of time left into the Fall. I get an average of 4 weeks longer in the Fall, as compared to my previous plants in-ground. Make sure you get the low DTM varieties for this time of year planting.