How late can I start strawberries in zone 5?
Are you starting from seed? As long as the strawberry is hardy for your zone, you can start them from seed now, get enough growth on them to overwinter, and get strawberries next year.
This is the time of year when strawberry plants, replant themselves by sending out runners. You can plant hardy strawberry plants as you would other fall perennials to fruit next year.
As far as I know you wont get any planted now to fruit this year, though with all the varieties out there I might be wrong.