We have a huge deer problem and have become exasperated with ineffective means of protecting our gardens. Before building an 8-foot fence, we are exploring additional options. We've been told, by a young environmental intern, that two 4-foot high wooden fences placed in parallel, and spaced just 4 feet apart from each other, creates an effective barrier against deer because deer can't judge how to jump these fences. Is this true? Are these dimensions correct?
You are not alone. Deer pressure is high and many are frustrated with trying to protect their gardens.
For right now, we'd recommend the tall poly deer fencing. It is pretty effective, admits sunlight and is not very visually noticeable.
While we have seen and heard about the closely spaced double fencing you mention, there is not currently research available to recommend one way or the other.
You don't say whether you are thinking of fencing your whole property or just a vegetable garden but you would want/need to plan for the shade a double wooden fence would cast as well as the cost and labor involved with it's installation.
Here is our Deer page with much more information on dealing with deer: