After the 16th your pots will probaby be fine getting watered 2 or 3 times a week, but I don't know what conditions they are in. If they get a lot of hot sun daily, or the conditions are windy they may need watering more often. Around here the plants are beginning to shut down for the winter.

Thanks, Jay. Some of my plants are up on a 4th floor rooftop, so they are getting both full sun and wind. However, I guess my question is...what if after Sep 16, they are essentially not getting watered at all anymore, aside from an occasional rainfall? (While someone WILL be staying here - but only from Sep 16 thru Sep 26 - they are under no obligation to water my plants, at all...and regardless, from Sep 26 onward, there will be No One here to water them at all, for the rest of this calendar year.

Put another way, at any other time of the growing season, if an outdoor container plant (one which normally likes daily watering) is 'never watered' for a number of weeks/months, it will eventually die. But around mid-September onward, and when most outdoor plants are getting ready to go dormant, anyway, maybe such plants (that were no longer getting watered) won't die per se, but might just go dormant a bit earlier? That's what I'm really trying to understand...when the dormancy timing might be starting up.... whether I really need to worry so much about my plants not getting watered at all, for the most part, from Sep 16 onward...

I am not a container expert, but I will give some insight from my own experiences. I have a plastic urn and a few pots on my porch into which I’ve thrown an odd assortment of perennials. Invariably, I never keep up with watering consistently through the season, and the pots dry up, and the plants often wither away and I think their gone. Then surprise, a few weeks later back they come. I have a larger pot in the back
Into which I’ve thrown random miscellaneous native perennials in, and it completely self manages with little care from me.