When to stop picking tomato/curcubit flowers in zone 5?

Hi, My tomato, tomatillo & curcubits (cukes, zucchinis, squashes) could all use some more growth before going to flower/fruit, but it being the beginning of July. Our first frosts come late September or early October. But with this Climate Weirdness (Polar Vortex) upon us, we may get an early  Sept frost. I guess I'm wondering how long these said plants take to go from flower to fruit, given good sun and decent irrigation?  Much Thanks

In my climate with cold radiant cooled nights, and modest daytime temperatures, it takes about 6 to 9 weeks from flowering to ripe fruit in tomatoes. Depends on variety.

Wow, welcome answer, cuz I live in zone 5 and feel a few of the plants still in flower stage, could use more growth before letting fruit set. Much Thanks

Your Subject Line had me quizzical. Pick the flowers? For what reason?

None of us bother here in Northwestern Ontario Canada that I'm aware of. Our growing season is so short, we're all, "Go to town. Quick Quick. Grow with you now." The plants seem to sort themselves out with setting fruit. I didn't realize it was different in warmer places. But likely, for us, our plants never see the size you might have in more southern locales.