Hello Betsy,

Thank you for contacting the UVM Extension helpline.

Numerous Extension resources note to bury the fence at least 12” deep in the ground. Also, it can be helpful to bend the bottom of the fencing at a 90 degree angle away from the garden for 12” or more. Similarly, another article notes to bend the bottom 6” (of the 12” buried) at an L-shaped angle leading away from the garden.

Woodchucks do climb so you’ll want to use tactics so they are unable to climb over the fence. Some options are: to bend the top 15” of the fence at a 45 degree angle outward away from the garden, or use bird or deer netting at the top so they cannot grasp and climb over it. If a fence is somewhat loose or flexible, they have a harder time climbing it, than if it’s sturdy. Be sure to extend the fence at a minimum of 3-4’ above the ground. If you don’t have luck with these measures, you could try an electric fence on the top as a last resort (articles below go into more detail on this option).

In addition to climbing, a University of Maine Extension article says, “woodchucks quickly learn to test a fence. They can squeeze through gaps, and juveniles can fit through large mesh sizes” (https://extension.umaine.edu/publications/7154e/). You’ll want to use a mesh size smaller than 2x2 inches. Use something more rugged than common chicken wire as it may rust too quickly and adult woodchucks may be able to push through it.

A UNH extension article says “Don’t neglect the gate. That is often the spot where defenses are the weakest. If they try to burrow underneath, install a board dug into the ground and flush with the bottom of the gate, or lay down a length of fencing as described above” (https://extension.unh.edu/resource/dealing-woodchuck-damage-fact-sheet-0).

In addition to the above two articles that lead to more in depth information, I’ve included an additional PennState Extension resource below:

https://extension.psu.edu/woodchucks

The benefit of taking on the work of adding a fence will also keep other unwanted critters out of the garden.

Good luck!