Earth Anchor Braces
Earth Anchors for Deer Fences
Use suitable trees as the posts at deer fence corners wherever possible. Lacking trees, you need earth anchors attached with a heavy wire or cable (see video). The earth anchor system can be used effectively with any corner post or corner approach post set in a cement footing.
This earth anchor system is appealing because all you have to do is screw the anchor into the ground (this can be hard in places with rocks or roots) and run a heavy metal wire designed for outdoor use between a securely anchored point on the fence post and the earth anchor’s handle. In most cases, compared to deer fence braces (an alternate bracing system), we have found earth anchors easier to install, less expensive, less visible, and more effective.
You can anchor a corner with earth anchors in two ways. One way anchors the corner post and requires only one earth anchor; but it leaves the earth anchor and its attachment cable outside the fence line, creating a potential lawnmower problem and tripping hazard. The other method braces the two posts approaching the corner post. This requires two earth anchors instead of one, but it puts the earth anchors and their cables right along the fence line, removing the lawnmower problem and tripping hazard.
If you are using the latter method, those parts of the fence between the corner approach posts and the corner post are not secured against sideways stress. So, where snow loads or falling tree branches are a problem, set the corner approach posts close to the corner post (within 6 to 10 feet, the closer the better). This will shorten the segments of fence that are not anchored. Similar reasoning applies to earth anchors used with gate approach posts and end approach posts.
One also needs to apply a measure of reasonableness. If the fence is a light polypropylene type defending a small California vegetable garden from one or two deer, and there are no snow load or tree limb problems, one may choose to dispense with earth anchors.
To anchor a post with an earth anchor, start by securing the earth anchor in the ground. To do this, screw the anchor into the ground at an angle (about 45 degrees, see illustration above), using a bar through the hole in the earth anchor’s handle for leverage. When you are done the earth anchor handle should be all that remains out of the ground, and this handle (as well as the earth anchor’s shaft below ground) should be pointing toward the top of its attachment post at a roughly 45 degree angle.
With a wooden attachment post, proceed as follows: If the post is square or rectangular, set it so that one of its sides faces the earth anchor. On the opposite side of this post, 3 or 4 inches down from the top, pound 3 two-inch u-nails four-fifths of the way into the wood. (Also do this if the post is a round wooden post.) These u-nails should be spaced an inch or so apart and should be oriented sideways, like three croquet wickets in a line, so that a wire can pass through them. Then string one end of your heavy wire through the hole in the earth anchor handle so that a foot or so of wire goes through the hole. Next, twist the wire tightly around itself four of five times (producing something that looks like a small hangman’s knot) to secure it to the earth anchor, and cut off any excess wire. Now figure how much wire will be needed to come up from the anchor handle and pass around the post and through the three U-nails. Cut a foot or so more than is needed, run the wire through the u-nails, and holding it good and taut (to take up any slack) twist it around itself four or five times to secure it to the post. Cut off all but about an inch of excess, in case you ever want to undo the wire. Your earth anchor is now firmly attached to the post.
Proceed as above when attaching the earth anchor to a metal post, but dispense with the u-nails. Instead, if the post is a round metal post, point the flanges of the brace band at the top toward the earth anchor. Then run the attachment wire under the bolt securing the brace band to the post, form another hangman’s knot, cut off the excess wire, and you are done. Or else, if the post is an angle-iron post, run the wire through a hole near the top of the post, form a hangman’s knot, and cut off the excess wire.