It's very true. I run a fence business in Dallas and Houston that has been around for 25 yrs. and we always add at least $15 a hole that has roots in it. They will tear up your digging machine and take, sometimes, up to 4 times as much work to dig the normal hole free of debris.
You can find metal fence posts at home depot or your local hardware store. They carry the posts you will need to support the metal fence or made of metal itself.
dont buy them
a fence
The strong or strongest part of a fence line are its posts. Posts are generally placed partly into the ground for permanent fencing. Posts provide structure for the entire fence, whether using slats or chain-link in between the posts. Even wood panels used instead of slats are typically weaker than the posts they are attached to in the fence line.
You can purchase plastic (most likely vinyl) fence posts online from such websites as Buy Vinyl Fence, Buy Direct Vinyl Fence, Lowe's, Penn Fence and Home Depot.
fence posts
dont buy them
Fence posts.
21 posts.
Everyone has seen fences that are no longer level. Though constructed with the greatest of care, these fences suffered from a simple, but fatal flaw. Their builders used too much concrete to set the posts. When setting wooden fence posts, the expert builder will dig a sufficiently sized hole and plumb and level the post in the hole. Then, and this is the important point, he will fill the hole only halfway with concrete. After the concrete sets, he fills the rest of the hole with soil. The result of this simple trick is less upheaval and settling of your wooden fence posts during the winter months.
5 vertical posts are needed. I---I---I---I---I
If you want your fence to last for a very long time I would definitely recommend cementing the posts in.