How to Anchor Posts in the Ground for an Arbor

The post anchoring procedure for arbor construction mirrors that of fences and basic post-and-beam structures. Although there are several options for anchoring posts, the simplest and most common method involves plunging the post directly into a post-hole filled with concrete. However, because this method leaves the post's butt exposed to ground moisture and pests, builders use decay-resistant lumber to build arbor posts, such as pressure-treated lumber or redwood. With posts properly set, the primary, load-bearing component of the arbor is complete.

The posts that support arbors anchor into the ground just like fence posts and patio cover posts.
  1. Use a shovel or post-hole digger to dig the hole for your arbor's posts. Although hole size varies according to project, standard post holes for 4-inch posts are approximately 10 inches in diameter and approximately 2 feet deep, or deep enough to engulf one-third of the post. Pound stakes around the perimeter of the holes with a mallet. Add an approximately 6-inch thick layer of gravel to each post hole.

  2. Place a post into one of the holes and have a helper hold the post upright. Place a post level against the side of the post and adjust the post's position until it stands plumb. Attach one side of a piece of scrap lumber to each stake with a hammer and nails. Attach the opposite side of each piece of scrap lumber to the post to brace the post in a plumb position. Level and brace the second arbor post.

  3. Pour dry post-hole cement into each post hole. Post-hole cement is specially formulated to absorb moisture from the air and the ground; add the dry mixture to the hole and lightly agitate the mix with a piece of scrap lumber to eliminate air pockets. Add a sprinkling of water to the top of the post-hole mix; do not fully wet the mix. Leave the concrete to set for at least 24 hours to 48 hours before removing the braces.


  • Post-hole cement does not require mixing.

About the Author

Based in Hawaii, Shane Grey began writing professionally in 2004. He draws on his construction experience to write instructional home and garden articles. In addition to freelance work, Grey has held a position as an in-house copywriter for an online retailer. He holds a Bachelor of Arts in theater arts from Humboldt State University.