Like humans and animals, plants need both water and nutrients (food) to survive. Most all plants use water to carry moisture and nutrients back and forth between the roots and leaves. Water, as well as nutrients, is normally taken up through the roots from the soil.
So, for example, a 3-month old puppy should be able to hold its urine for approximately 4 hours in a pinch. This means that if you have a properly toilet trained 4-month-old puppy that, theoretically, can hold its urine for 5 hours, and you shut that puppy in a crate for 6 or 7 hours, you are courting disaster.
Aiming for Success. Generally, a puppy can hold his bowels and bladder for the number of hours equal to his age in months plus one. Therefore, a 12-week-old puppy can wait four hours between potty breaks, while a 16-week-old pup can wait up to five hours.