If you want to instal a plastic fence post, take care to avoid common mistakes that compromise the quality of performance of the fence. The post needs to be planted deeply enough in the soil, posts should be close enough together to handle the stress and weight they must support, and you should always dig post holes rather than driving the post into the ground.
Make sure that you plastic fence post is buried deeply enough. If the hole is too shallow, the weight the plastic rails can cause the posts to lean or fall over. No matter how short a plastic fence post is, the hole should be at least 12 inches deep. A good rule of thumb is to make the hole 1/3 the length of the post.
A plastic fence is not design to deal with stresses and tension. When there is too much weight placed on a section of fence, that section will sag. To prevent this, space the posts no more than 12 feet apart.
Do not drive a plastic fence post into the ground. Plastic is not meant to handle heavy impacts, and driving it down will cause the material to bend, warp or completely break. Always dig a post hole. It may take a little longer, but plastic posts are designed to be installed that way.