Small Duckbill Anchors for Tree Guying

Small duckbill anchors are drive-in earth anchors that let you guy a newly planted tree without wooden stakes. You drive the anchor into the ground with a drive rod, pull back on the cable, and the anchor turns sideways in the soil and locks. They are quick to set and out of the way once installed.

How duckbill earth anchors work

A duckbill earth anchor looks like a small metal bill with a cable attached. You set it on the end of a drive rod and hammer it into the ground at an angle away from the tree. Pull the rod out, then pull up hard on the cable. The anchor pivots crosswise in the soil, like a toggle bolt in drywall, and resists further pulling.

That load-lock step matters. An anchor that has not turned holds very little. Pull until you feel it set before attaching the guy to the tree.

The design is simple and that is the appeal. There are no stakes sticking up for kids or mowers to hit, and the only thing left above ground is the guy cable running to the trunk. On a commercial planting with many trees, a crew can set a set of duckbill earth anchors in minutes per tree.

Guying a newly planted tree

For most trees, three duckbill anchors spaced evenly around the root ball give support from every direction. Keep the anchors outside the root ball, and run each guy to a soft collar or strap on the trunk, never bare wire on bark.

Leave a little slack so the tree can move. Terminate the cable with a thimble and wire rope clamps or the hardware supplied in a duckbill anchor kit.

Angle the guys so they meet the trunk at roughly one-third to two-thirds of its height, with the anchor far enough out to give a reasonable angle. Flag the guys with tape or covers so people do not walk into them.

Soil, size and limits

Holding power depends on soil. Dense clay holds well; loose sand and wet soil hold less. Small anchors are for small trees. For larger caliper trees, step up to a bigger anchor size and check the maker's chart.

Call before you dig. Driving anchors into buried utility lines is a real hazard, so get locates done first.

A duckbill anchor kit typically includes the anchors with cable attached and the hardware to terminate them. Check what your kit includes and whether you need a drive rod, which is reusable and worth keeping in the truck.

Removing the guying

Plan to remove guys after a season or so, once the roots have established. Cut the cable at ground level and leave the anchor in place, or dig it out if the site needs it clear.

If the tree still moves too much at removal time, check the planting depth and root ball before you add the guys back. Guying cannot fix a tree planted too deep or a root ball that has fallen apart. Note anchor locations on the work order so the next crew knows where the cable runs are, especially near lawns that get aerated.