i'm going out of town...how long can tomatoe and pepper plants survive
in a pot without watering?

ersalan

How long is a piece of string?

The answer to your question depends on pot shape, glazing, size, size of plant,
temperature, wind, weeds in the pot, insolation, humidity, soil type...

If these are small plants, big enough pots that the plants look lost, soil
with lots of organic matter, and temps and winds should be mild, they'll
probably do fine for 2-3 days. But if you want to make sure, or this
will be a fairly common occurence, install some drip irrigation.
It'll increase your harvestable fruit, too, and probably decrease
pest and disease
problems.

Kay