How long will vegetables stay fresh at room temperature?

Depends on how fresh they are and if they have any bruises. Eggplant, farmer's market peppers, potatoes, tomatoes can last 7-10 days (even more if the temperature is not too high). Vegetables that one usually stores in the fridge like celery sticks and salad will lose their crispness quite rapidly( half an hour). If you bought it from a store's fridge put it in the refrigerator at home. They will not last at room temperature.