While some fences require strong reinforcement, such as those used to contain livestock and children, others are for decorative purposes only. As opposed to strong, permanent fence posts that need concrete to keep them in place, temporary fences, as well as decorative fences, require just a little soil compaction and some pea gravel to keep them standing vertical.
Hammer a garden stake at each end of where you want your fence to go and stretch a taught string between the two posts. This will ensure that you dig your holes in a straight line, keeping your fence straight as well.
Measure and mark off the distance for your fence posts. Use a measuring tape and spray paint to mark a hole for each fence post every 1.2 to 1.5 m (4 to 5 feet). Placing them closer together will increase the strength of the fence.
Dig the holes for your posts with a posthole digger or a long, narrow spade. Remove the soil to a depth equal to one-third the length of your fence post. Make the holes at least three times the diameter of your post.
Compress the soil at the bottom of your holes with a soil tamper or a heavy piece of timber, pounding the soil firmly 10 to 12 times. Use a sharp stick to poke the bottom of the holes. If the stick sinks easily into the soil, tamp it some more.
Extend your measuring tape down the side of the first hole. Keeping the end of the measuring tape firmly against the bottom of the hole, pour a 12.5 to 15 cm (5 to 6 inch) layer of gravel into the hole. Remove your measuring tape and repeat this procedure with the additional holes, keeping the level of gravel equal in the holes.
Place a post in the first hole. Use a carpenter's level along two perpendicular sides of the post to keep your post from leaning. Have a friend hold the post in place while you shovel pea gravel around the sides. Fill the hole about 12.5 cm (5 inches) from the surface of the surrounding soil with the gravel and top off the remainder with backfill soil. Use a tamper to compact the soil over the gravel. Add additional soil to make the level of the soil over the gravel level with the surrounding surface.