Hybrid high-tensile/hardware cloth exclusion fence (and grape trellis) design challenges

Hello all!

I’m a long-time reader, but first time poster. We finally purchased a few acres last year and we’re now ready to start building our homestead dream, starting with veggies! There’s one problem: we’ve got deer, groundhogs, and moles and we need to build a non-electric exclusion fence for our 60x100’ garden this spring or we won’t get much of a harvest. I’d like your advice on how you would solve some of the lingering challenges I have or even just improve the design efficiency of my current plan. Thank you in advance for your musings!

My current thought on fencing is to do a combination of ½”x½” hardware cloth at the bottom (18” below ground to 5 feet above) to exclude the rodents and 12.5 gauge high tensile (HT) wire spaced out from there up to 8 feet above ground to discourage the deer. (See attached fencing material diagram) I know hardware cloth up to 60” is not necessary strictly speaking for the rodents, but I’d also like to run a pair of high tensile lines on the inside of the fence at about 54” and 30” to grow some grapes in Top Wire Cordon fashion and having that fine hardware cloth so high will keep deer from munching on the vines. If we’re going to the trouble of installing a sturdy fence, why not get the most out of it as a grape support and protection system too?

For the fence support structure, I planned on 6” diameter 12 foot long pressure treated posts sunk 48” deep in a single H-brace assembly at ends and corners (with the cross brace being a 4” diameter 8 feet long post placed about ⅔ up the total height, i.e. about 5.5 feet). I would have 4” diameter 10 foot long pressure treated posts and 10 foot T-posts (both 24” deep) alternating along the fence line at 12.5 foot spacing to act as line posts. (See attached fencing support diagram).

After a lot of research and planning, that’s the best design I’ve been able to come up with that checks off all the boxes without any redundancies and without too much expense. Before I spend two grand and lots of my free time doing it myself, I wanted to discuss a few lingering concerns that I have with you all first:

1) How best to prevent rust with ACQ wood: Even though we won’t be electrifying our fence, I was considering fitting the HT wires with rubber insulators at their connections to the wood posts. The reason for this is because all our wood posts will be “AC2”, a wood that is treated with much safer micronized copper quaternary (ACQ) instead of the traditional copper chromium arsenate (CCA). ACQ, however, is much more corrosive than CCA, and manufacturers recommend using hot dipped galvanized metal for direct contact with this wood, since hot dipped has the highest zinc coating that you can get readily. The highest zinc HT wire I can find is class 3 galvanized (less zinc than hot dipped), so I’m thinking putting a plastic barrier between the HT wire and the ACQ wood would help the wire last longer. The non-existence of hot dipped regular wire mesh was the main reason I decided against it for the lower portions of the fencing (that and all the openings on those were too large to exclude rodents effectively); ½” hardware cloth is readily available in hot dipped and has holes small enough to keep out all the critters. Do any of you have any experience with these metals and AC2/ACQ wood? Do you think the added insulators on the wire would be worth the time and cost?

2) Can I mix high tensile and non high tensile materials: Though ½” hardware cloth seems the right choice, I’m not sure how (if?) I can attach it to posts that also have high tensile wires on them. If I just staple the hardware cloth the same way I would the HT wire, I’m concerned that the cloth will bow or burst since it doesn’t have the tensile characteristic the other wire does and it will only be able to slide about ½” under the staple. Do any of you have experience using non high tensile hardware cloth or larger wire mesh and high tensile wires on the same posts?  Any suggestions on how to attach a hardware cloth as fine as ½”? Using high tensile woven deer mesh would solve the high tensile/non high tensile concern, but I can’t find any hot dipped versions and the smallest it gets (as far as I can find) is 3”x3”, which certainly won’t keep little critters out and may not stop the deer from eating those grapes.

3) Can a single H-brace hold this fence design: I’ve seen several university extensions say that 6 high tensile wires (maybe 8 in basically slope-free clay soil, which we have) is the limit for how many lines you can support on a single H-brace assembly. I was planning on using two HT lines for a Top Wire Cordon grape trellis, then five more spaced from the top of the hardware cloth to the top of the posts - a total of seven wires. So I’d feel safe with that plan - especially since my line post spacing is rather short (12.5’) and the longest span I have between brace assemblies is a little less than 100 feet - except that there’s the hardware cloth to consider too. Do you think my single H-brace assemblies, set so close, will be able to handle 7 HT wires and the non HT mesh as well, particularly as most of the HT wires will be near the top of the posts? Should I use fewer HT lines with the single H-braces or do you think I could handle more? I’m asking if I could handle more, since I’ve seen those high tensile woven wire mesh for deer on 8 foot fences and that ends up being almost twice as many horizontal HT lines than the 8-line limit I keep seeing… so perhaps that limit of 8 was for lower cattle fences only?

4) How the heck do you make a plumb gate: Most ‘best practices’ articles on high tension fences say that you should lean your anchor posts slightly away from the direction your wire lines are pulling. That makes sense, but one of the idiosyncrasies of our garden area requires us to put our north and south gates right up against the corners with the eastern fence line. (See attached fencing support diagram) Because of that, I can’t figure out how to construct gates that close properly.  Using the south gate as an example, if I tip the anchor posts (which are also the gate posts) against the wires they anchor, I’ll have one gate post out of plumb leaning into the gateway and the other post will be leaning south out of line with its gate post partner. Have any of you made a corner gate like this? Should I just not lean these anchors, or is there some special gate hanging fastener or trick that I’m missing?

5) Is integrating a trellis in this fence a bad idea: Has anyone tried integrating their fence with a trellis for growing grapes? The 54” height I’m proposing would allow me to do a slightly lower version of the Top Wire Cordon growing method while protecting the fruit from deer. The knitty gritty structural questions are obviously more important, but I’d love to hear any tips or thoughts you may have.

I know that was A LOT of information, but I wanted to paint you an accurate picture for the best chance for specific advice. I’ve been thinking about this for ages and I think I’ve gotten to the point where only personal help from experienced folks like you can put these questions to rest. Thank you so much again!

Hi Mark, thanks for making the step into posting.  Good description and great sketches.

I don't have any high tension knowledge so I'll defer to others on that.  

On my 60x120 fence I used low tension plastic deer fencing for the top 6.5 feet and chicken wire for the bottom to keep out rabbits.  I used 4x6's for the corners and didn't brace them.  I used 1" EMT conduit every 15' to hold the fence up (with black zip ties).  I didn't have to worry about moles and I didn't realize chipmunks were as big a problem as they turned out to be.  FYI a chipmunk can take a run at a chicken wire fence and dive through a hole without slowing down.  I used Tenax fencing that you can get from Amazon.

If you used plastic fencing (like Tenax) it would allow you to skip the hardware cloth for the area above rabbit height which could save a bunch of money.