The Ideal Height
When installing a picket fence, it's important to make sure the fence panels are off the ground. Wood panels can begin to show signs of rot if they are in direct contact with ground moisture, and even vinyl fencing will be more susceptible to mildew and discoloration. Therefore, you should set your fence panels 2 to 5 inches off the ground. The distance ensures that you maintain a secure boundary for pets or young children while still protecting your fence from the elements.
When to Deviate
Although 2 to 5 inches is the height you should aim for, there are times when you will want to raise you fence panels a little higher off the ground. If you have a lot of long vegetation growing around your fence line, 5 inches may not be high enough to keep away severe moisture. In that case, raise your fence panels up just high enough to avoid the dense base of vegetation.
Most situations call for a picket fence that is 2 to 5 inches off the ground. However, it's important to pay attention to the environment around the fence line, and if necessary, position the fence a couple of inches higher.