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.
In other words, if your puppy is three months old, he should be capable of holding it for four hours. Unfortunately, this means you may be in for a few restless nights until housetraining really kicks in. With patience and persistence from you, this period should not last long, Millan says. 4. Keep your cool.