What to Plant in May and June in Guelph and Zone 5 area.
It's September. If you have a cold frame or a greenhouse you can still plant lettuces. But, don't delay. It's getting late but there are still about 12 hours of daylight in the days. Start the below indoors and then move them out once they've sprouted unless it's going to be below 10 C during the day.
There are still lots of seeds that can be planted now for slow cold frame and greenhouse growth over winter.
Winter Spinach, Mizuna, Leeks, kale, parsley, arugula and some lettuces. Unfortunately I only have Winter Spinach, Mizuna and Arugula right now.