I live in bear country. Every year I have visitors checking out my chicken coop, bee hives, and food forest. Yes, they take a peek through my living room window not even blinking an eye when my three dogs bark at them. Bears are, next to coyotes, mountain lions, and eagles, the main predators on my homestead.
So, when I decided to get bees, I did a ton of research on the best way to protect my bees. There was not one set-up I really liked, so I took a bunch of ideas and put together my own seasonal bear-proof fencing; you might call it a fortress, but so far, it is working.
How does an electric fence work?
When I started reading up on my bear fence I felt like I was back in school. Positive and negative charge, circuit completion, grounding… let me see if I can give you a basic idea: An electric fence uses electric shocks to deter, in this case, the bear from getting into my bee hives. It is set up to create a circuit that, only if completed, will shock the animal.
An electric fence circuit is composed of different parts: The fence charger with a negative and a positive outlet, the positive wire, and the negative or grounding wire/rod/fencing.
In my setup, the energizer fence terminal (positive outlet) is connected to the insulated fence wires (hot). The energizer earth terminal (negative outlet) is connected to 1. The galvanized metal stakes (grounding rods) driven into the ground, the welded wire fencing put up behind the fence wires, the welded wire fencing put on the ground surrounding the fence, and the grounding (negative) fence wire put up in between the positive wires.
The bear has to be in contact with both negative and positive charge at the same time to get shocked. That is called ‘circuit completion.’ That is why for example, a bird sitting on the wire will not receive a shock. When putting up your fencing you really want to make sure you have a solid grounding system (grounding rods and/or welded wire on the ground, etc.) to reach full protection.
What to Consider before you start digging?
Location
When I choose the location for my hives I took several questions into consideration:
•Is this a snow loaded area during the long winter which would make it hard to access?
•Where does the sun hit the area, especially during the winter?
•Is there some wind protection? The cold is not the bees’ worst enemy; it is actually the strong winds.
•Is there sufficient amount of space to build a bigger enclosure than I think I need (in case I want to add hive boxes down the road)?
•Is the grass growing “wild and tall”? This would require for me to clear cut underneath the electric wire all the time.
Size of area fenced in
I wanted a bigger area with the option to add hive boxes during the years to come and build an earthen shelter for my bees so they would be more protected from the gust winter storms. I needed space and chose my enclosure to be 50×60 feet.
Height of fence
There are different opinions regarding the height of the enclosure. I opted for 5.5 feet.
Voltage
Long-haired animals, like the bear, require a minimum voltage of 5,000 volts to receive a shock. Pretty common for a bear fence is 12,000 volts with amperage of one or less to deliver a painful enough shock. 12 volt batteries are pretty standard and you can find them in most ranch supply stores.
Materials
I am listen below the things I needed to build my fence, plan accordingly if you make a bigger or smaller fence.
| Items | Quantity |
| Wooden non-treated or cedar fence posts.I bought 8 footers since I wanted the welded wire portion of the fence to be 5 feet high, being lifted off the ground 1/2 a foot. So, two feet in the ground, 1/2 foot before the welded wire starts, and a little extra on top | 18 |
| Grounding rods | 3 at least 3 feet long |
| Ground rod clamps which go with the grounding rods | 3 |
| Garden staples to attach the welded wire fencing to the ground | 50 |
| Gate handles | 7 |
| Electric wire: 12 to 16 gauge wire is the most common size range used in electric fencing | Depending on how many rows of wire you are putting up and if you have other projects (i.e. chicken run) I would buy a big spool |
| Split bolt wire connectors to connect the wires to each other | 2 packages |
| Wood Post Screw-in Ring Insulator | 100 |
| Corner lag insulators | Those come in packages of 5. I bought 4 packages |
| Wood post gate anchor insulator | 14 |
| Bull nose strainer | 5 insulated and 1 non-insulated bull nose/wire strainer |
| Insulated tubes to tie around posts | 2 packages of 10 |
| Crimp sleeves (size depends on the wire you buy). | 0ne box of 100 |
| Fence charger/energizer | There are two types of fence chargers: 1. Mains powered, you plug them into a mains power supply let’s say at your house and 2. Battery/Solar powered: Is what I have because you can just leave them outside no matter where the hives are |
| 12 volt deep-cycle battery | 1 |
| T-posts for corner enforcement | 4 |
| Fencing nails | 1 bucket (I have them around, so I didn’t count…) |
| 12 foot galvanized wires to attach to corner/T-posts | 4 |
| Clamps to hold heavy wire on corner posts together (size depends on wire diameter you get) | 16 |
Tools you need
- Posthole digger
- Shovel
- Level
- Pliers
- Wire cutters
- Hammer
- Patience
- Drill (to pre-drill the holes in the posts)
- Fence tensioner
- Tamping tool
- Tape measure
Where to Start?
1. Fence posts
Once you determined where you want the enclosure, you want to mark/flag the individual posts (mine are 8 feet apart) before you start digging. Note that you want the corner posts to be braced in some way or another. I chose to use heavy wire and anchor it to a T-post pounded in in the ground in an angle. To achieve the tension you want, it helps to wrap a ratchet strap around the corner post, tighten it, and then close the clamps. Tamp each post really well, so they will not move when you stretch the welded wire.
2. Putting welded wire up
You want the welded wire fencing to go on the inside of the enclosure, with the exception of the corner posts which you stretch the fencing around. Use a fence tensioner and if you have a tractor to pull the fencing tight. If not, a camelong is really helpful. Once the fence is stretched right, nail it to the wooden posts.
3. Putting electric wire up
Mark your posts at 1, 2, 3, 3.5, 4, and 5 feet, pre-drill and put the screw-in insulators in. From the ground up I place: 1. Bottom wire (hot), 2. Hot wire 3. Hot wire 4. Ground wire 5. Hot wire 6. Ground wire. You want the wire to dead end, not go up and around. The wire does not have to be super tight.
4. Building your gate
I made the gate wide enough so I could drive in with my little tractor. Think about what you want to be able to get through the gate and design it accordingly: a wheelbarrow, a lawnmower? Also, I added 2 hot and 1 ground wire to the gate to give extra protection.
5. Installing charger and grounding rods
You want the fence charger to be inside the fence, close to the gate. I have it set up so I can reach inside and unhook the hot wire at any point. I have it sitting on the ground, some people like attaching it to a pole.
6. Grounding
Proper grounding is essential and maybe I overdid it a little, but here is what I did:
• I put three grounding rods, 10 feet apart, along the inside parameter of the fence. You want to connect those with wire and hook them up to the negative charge on your charger
• To improve the ground around the perimeter of the fence I added long pieces of the welded wire I cut in half (length-wise) laying on the ground around the outside of the fence.
• And, lastly, I added one negative wire to the whole parameter and 2 negative wires to the gate.
With all of these different methods of grounding you want to make sure that they are properly connected.
7. Testing your fence
You do want to make sure you connected everything correctly and the fence actually works.
The image below shows how electricity flows.
Image from http://www.gallagherusa.com/electric-fencing/electricfence101.aspx
Maintance
- You need to make sure that any grass growing close to the fence is being cut on a regular basis so the hot wires are not being grounded out by sticks, vegetation, or other stuff
- Check your battery and make sure both terminals are corrosion free
- You might want to pour water around your grounding rods during periods of drought. This will increase the conduction.
